Start of by hanging on the bar, you want to make sure you’re looking forward and that your legs are slightly in front of you.
Tense your glutes, grip, abs and start pulling up.
You want to pull towards your chest so if you can get higher than chin to the bar, do so.
Once you’re at the highest position hold for a second and lower all the way down till your arms lock out.
You want to perform the movement slowly and control every inch of it.