I'll try and find a step by step guide inshAllah, but i have only this for now
Tahajjud – to wake up in the middle of the night for Tahajjud salaah is very beneficial. Allah SWT is very appreciative of this salaah. This is the one which brings the most rewards of all nafl salaah.
One should perform anything from four to twelve rakaahs for the Tahajjud salaah.
A narration relates that four rakaahs of Tahajjud is equal to four rakaahs performed on Laylatul Qadr. The performance brings one closer to Allah, is kaffara for previous sins and it is prohibitive for future sins. Allah SWT bestows his rahma to those who get up to recite this salaah.
Allah SWT sends a message in the last part of the night saying if there is any appeal to Him, it shall be answered and if there is one seeking His forgiveness, he shall be forgiven. The doors of His mercy are opened and this is the time when prayers are accepted. One should take advantage of performing this salaah in the month of Ramadhaan and perform this salaah before suhoor.