Perform the Ghusl (bath) and Wuzu (ablution).
Then recite four rakats prayer.
In each rakat after Surah Hamd recite Surah Tawheed/Ikhlaas thrice and Surah Falaq once and Surah Naas once.
And after the prayer do recite 70 times “Astaghfirullaah Rabbee Wa Atoobu Ilayh”
Then recite the following Duaa: “Laa Hawla Walaa Quwwata illaa Billaahil Aliyyil Adhweem, Yaa Azeezu Yaa Ghaffaar, ighfirlee Dhunoobee, wa Dhunoobi Jamee’il Mu’mineena Wal Mu’minaat, Fa innahoo Laa Yaghfirudh Dhunooba illa Anta”.
And the Holy Prophet (s.a.w.s.) said:
No servant of my Ummat performs this prayer that a caller does not calls out from the sky: O slave of Allah! This deed has been elevated and your repentance (Tawbah) has been accepted and your sins are forgiven.
An angel will call out beneath the heavens: O slave of Allah! Congratulations to you and your family members.
An angel would call out: Your enemy would be satisfied with you on the day of Judgment. Another angel would call out: O slave of Allah! You would leave this world with faith. You would not be arrested. Your grave shall be expansive and illuminated.
Another angel would call out: O slave of Allah! Your parents are happy with you though they were dissatisfied with you before. Your parents and your descendants shall get salvation and there shall be increase in the livelihood in the world and the hereafter.
Hazrat Jibraeel (a.s.) would call out: At the time of death I would come with the Angel of death and would be kind to you and you shall not have any problem. Your body would not be pained at the time the soul is taken out.
The people asked: O Messenger of Allah (s.a.w.s.), how should one perform this if one desires to perform it in any other month? The Prophet (s.a.) replied:
In the same way with the merits.
And said: Jibraeel has taught me these words on the night of ascension (Shab-e-Me’raj).