A. The morning blessings:
B. The reading of the Torah:
How many scrolls are removed? Two Sifrei Torah are removed from the Ark for the Torah reading of Shacharis on Yom Kippur.
What is read in the first scroll? In the first scroll, the section speaking of the death of the sons of Aharon, and of the Yom Kippur service, is read. This is found in the beginning of Parshas Acharei Mos.
Second scroll-Maftir: Maftir is read from the second Sefer Torah. The section discussing the sacrifices offered on Yom Kippur is read from Parshas Pinchas.
Haftorah: The Haftorah of “Solu Solu” is read from Isaiah, as it discusses repentance and fasting.
How many people are called up to the Torah? A total of six men are called up for an Aliyah in the first Torah scroll, unless Yom Kippur falls on Shabbos, in which case seven people are called up. One person is called up to read Maftir.
Chazan of Musaf: Some communities have a custom to give one of the Aliyos to the Chazan of Musaf. [The above people are considered Chiyuvim in areas that follow this custom. However, this only applies if the Chazan does not take money for his work. However, those Chazanim who get paid are not considered a Chiyuv at all. Nevertheless some write that it is proper to give them an Aliyah even in such a case. Some Poskim rule that the above law however is only in a case that the Aliyah’s are not sold in the Shul. If, however, the Aliyos are sold then there are no Chiyuvim, even for the Baal Tefila, Baal Yartzite, Sandek etc, and all the Aliyos may be sold to highest bidder.]
Being distressed from the deaths of Aharon’s sons: One who is distressed over the death of the sons of Aharon and is brought to tears due to it, is forgiven for his sins, and receives protection that his children will not die in his lifetime.
May one who is not fasting for medical reasons be called to the Torah?
One who is not fasting may nevertheless be called up for the Torah reading of Shacharis. It is however questionable whether he may be called up for the Mincha Torah reading. Some Poskim however rule he may be called up even for Mincha.
In which tune is the Torah to be read?
During Shacharis, the Torah is read in the same High Holiday Nigun that it is read on Rosh Hashanah. However, by Mincha it is read in the regular Torah reading tone.
C. A Bris that falls on Yom Kippur:
When should the Bris take place? The Bris is to take place between after the reading of the Torah before Musaf. Some are accustomed to have it take place prior to Ashreiy of Musaf, while others first say Ashreiy and then do the Bris. If the Bris is not taking place in the Shul, then after the Torah reading, the scroll is to be returned to the Aron and the congregation is to go to the location of the Bris. After the Bris, they are to return to Shul for Musaf.
Is wine to be used for the Milah? Some are accustomed to omit the use of a cup of wine when a Bris takes place on Yom Kippur, as in any event there is no one who is allowed to drink it. Others are accustomed to use a cup of wine, as is the usual practice, and then give it to drink to the child who is being circumcised. Others are accustomed to follow the same practice as Tishe Beav, which is to use a cup of wine and give it to drink to any child who is under the age of Chinuch.
The final ruling: One is not to initially follow this latter opinion although those that do so need not be protested. [Practically one is to follow the custom of his community. Hiskashrus writes to follow the second opinion, which is to give the wine to the actual infant.]
The Halel prayer is not recited on Yom Kippur.
Saying Halel in Tehillim: Those who say Tehillim on a daily basis and reach the psalms of Halel on Yom Kippur [as part of their regular cycle] are permitted to recite these psalms as usual. [However, those who are not saying the Tehillim as part of any cycle, may not specifically recite the psalms of Halel in Tehillim.]
On Yom Kippur, one may not specifically recite the psalms of Halel in Tehillim. If, however, one is saying a regular cycle of Tehillim he is not required to skip the psalms of Halel.
The custom is to recite Yizkor on Yom Kippur, after the Torah reading.
No Minyan: Yizkor may be recited even if a Minyan is not present.
Candle: It is not the Chabad custom to light a candle for Yizkor. The Rebbe and Rebbe Rayatz did not light Yizkor candles.
Aliyah: It is not the custom to be particular to receive an Aliyah on the day of Yizkor.
How to mention the name: One is to mention the name of the Niftar together with the name of his mother during Yizkor, such as Eliezer Ben Bashe Leah. One does not mention his father’s name.
Mentioning the Rebbeim: It is customary amongst Chassidim to mention the name of the Rebbeim whom they were Chassidim of, in Yizkor. This has an effect on the Chassid saying it.
Mentioning men and women separately: Men and women are to be mentioned separately in Yizkor.
Charity: One is to pledge charity during Yizkor, on behalf of the soul of the deceased.
Yizkor during the first year of Aveilus:
When Yizkor is taking place during the first year of Aveilus, the mourner remains in Shul for Yizkor, although does not recite anything while there. He is not to recite the Yizkor even quietly.
After 12 months in a leap year: One who is still prior to the first Yartzite, but is past 12 months of mourning, is to remain in Shul and recite Yizkor regularly.
If the mourner needs to say Yizkor for another parent who is past the 1st year: If one is within the year of one parent and past the year for another parent, then only the parent’s name that is past the year is to be mentioned in Yizkor.
 Siddur based on Arizal in Peri Eitz Chaim Shaar Habrachos 4; opinion brought in Levush 554/17; Sefer Haminhagim p. 47 [Hebrew]. So also rule the following Poskim: Kesher Gudal 5/19; Zechor Leavraham 1/300; Beis Oveid 10; Shaareiy Teshuvah 46/12; Kaf Hachaim Falagi 9/11; Yifei Laleiv 3/4; Ben Ish Chaiy Vayeishev 12; Maaseh Rav 9; Mamar Mordechaiy 46/10; Kaf Hachaim 46/17; See also Sdei Chemed Peas Hasadeh Asifas Dinim Bein Hameitzarim 2/9 [Vol. 8 p. 765 Kehos]; Otzer Minhagei Chabad p. 217; 250; Chikrei Minhagim p. 185
Other Opinions: The following Poskim rule the blessing is to be recited as usual: Levush ibid; M”B 554/31; Alef Hamagen 619/47; Darkei Chaim Veshalom 775. The Gr”a in Maaseh Rav 9 adds that the blessing of Hamavir Sheiyna is likewise omitted.
 This is due to that one is not allowed to wear leather shoes on these dates, and thus there is no worldly pleasure received from leather shoes on these days. [Peri Eitz Chaim ibid]
 Sefer Haminhagim p.47 [Hebrew]; Hayom Yom 9th of Av and 10th of Tishreiy; This was a directive received from the Tzemach Tzedek in name of the Alter Rebbe. So also rules Ben Ish Chaiy ibid
Other Opinions: Some Poskim [Gra in Maaseh Rav 9; Mamar Mordechai 46/10] rule that the blessing is to be said at night after the fast.
 Admur 621/1
 Admur 584/8; Rama 584/2 in name of Kol Bo
 The community of Pozna. [Levush and M”A 584/6]
 Kitzur Shlah; Elya Raba 584/9; Machatzis Hashekel; P”M 584 A”A 6; M”E 584/22; M”B 584/9; Kaf Hachaim 584/24
 Alef Hamagen 584/27 based on the reason of the Levush recorded above.
 Aruch Hashulchan 584/3; Shaareiy Efraim 2/15 regarding a Baal Yartzite and Sandek
 Admur 621/15
 Rav Akiva Eiger 24; See Piskeiy Teshuvos 621/1
 Minchas Elazar 2/74
 Admur 621/3
 The reason: As it is not respectful for people to leave the Shul while the Sifrei Torah are still out of their set place. [ibid]
 Even a child cannot drink it, as although by Tishe Beav we rule leniently that a child may be given to drink being that it is an uncommon event, nevertheless, by Yom Kippur, since the fast is Biblical, we are stringent despite the fact that the event is uncommon. [621/4]
 Now, although in general to be able to make a blessing for a child the child must be of age Chinuch, nevertheless, here since the blessing is done for the sake of the circumcised child, he may be given to drink. [621/5]
 Admur 621/6
 948 p. 13
 Admur 584/1; Michaber 584/1; R”H 32a
 The reason: As Hashem is sitting in judgment with the books of life and death open before him, and hence how can one say Shira. [ibid] This is because it is improper for one to be in a state of joy when he is being judged and should have a face of awe and trepidation. [Taz 583/1; M”B 584/1] Likewise, it is improper to be in joy when others are being written in the book of opposite of life.
 Admur ibid; M”A 584/1; Elya Raba 581/1; Chayeh Adam 139/11; M”E 584/19; M”B 584/2; Kaf Hachaim 581/2
 The reason: As they are not saying the psalms of Halel as hymns of praise but rather as a request and supplication. [ibid]
 So is implied from Admur who specifically mentions the allowance of saying Tehillim for one who says it on a daily basis and just happens to reach these psalms on Rosh Hashanah. This implies that to pick out the Halel section in Tehillim is forbidden even if one plans on saying it as part of Tehillim.
 Admur 621/14
 Gesher Hachaim 31/6
 Shaareiy Efraim 10/32
 The reason: This is due to Ayin Hara.
 Hamelech Bemisibo 1/321 [printed in Shulchan Menachem 2/250]; However, in Luach Kolel Chabad it says to light it.
 Igros Kodesh 3/220 [printed in Shulchan Menachem 2/250]
 Kaf Hachaim 284/37 based on Zohar; Siddur Torah Or; Hamelech Bemisibo 2/166; Igros Kodesh Miluim, [printed in Shulchan Menachem 2/251]; Mishnas Sachir 2/233 that so is the custom in Ungarin; See Divrei Torah Munkatch 2/90; Nitei Gavriel 79/14 in name of Poskim
Other customs: Some are accustomed to mention the name of the father by Yizkor. [See Zohar brought in Hamelech Bemisibo ibid; Mishnas Sachir 2/233 that so is the custom in Poland; Nitei Gavriel 79/14 in name of Poskim and that so is the custom]
 Toras Menachem 46/343 [printed in Shulchan Menachem 2/252]
 Nitei Gavriel Aveilus 79/13
 Igros Kodesh 3/220 [printed in Shulchan Menachem 2/251]; Hamelech Bemisibo 1/309; Otzer Minhagei Chabad Yom Kippur p. 222
 This is learned from a play on words “Eitz Chaim Hi Lamachazikim Ba”, that one is to hold on to the Eitz Chaim for long life. [Hamelech Bemisibo ibid]
 See Admur 621/14
 Sefer Haminhagim p. 125 [English]
 So is the final ruling of the Rebbe in Sefer Haminhagim ibid, unlike Igros Kodesh 3/7 [printed Shulchan Menachem 5/308] in which the Rebbe directs to recite the Yizkor silently
 Directive of Rebbe Rashab to Rav Yaakov Landa brought in Otzer Minhagei Chabad Yom Kippur 195