Al-jawab billahi at-taufeeq (the answer with Allah’s guidance)
Details of how men should remove their hair in Umrah or Hajj:
According to the Shari’ah, a person completing Umrah or Hajj have two options of removing the hair; a) Halq (shave) and, b) Qasr (shorten)
Halq is when the entire head is shaved and more virtuous than Qasr. Rasulullah (Sallalahu-Alaihi-Wasallam) shaved his hair when he performed Hajj. (Mishkaat, pg 232 Thanvi)
Rasulullah made Du’a three times for those shaved their hair and made Du’a once for those who trimmed their hair (ibid).
According to the Hanafis the necessary amount of hair (for Halq and Qasr) that should be removed is 1/4th of the head. But the entire head is better and virtous.
(Sharh Nawawi ‘Ala Saheeh-il Muslim Vol. 1 Pg. 420- Darse Tirmidhi Vol. 3 Pg. 186)
Also, whoever has no hair they should apply the razor over their head. (Al Bada’i As Sana’i Vol.2 Pg.140- Darse Tirmidhi Vol. 3 Pg.187)
Details of how women should remove their hair in Umrah or Hajj:
Women should cut a finger tip’s length from their hair in Umrah or Hajj. (Al Bada’i As Sana’i Vol. 2 Pg. 141- Darse Tirmidhi Vol. 3 Pg. 187)
And Only Allah Ta’ala Knows Best.
Moulana Qamruz Zaman