Adjust tower unit. Fold back cross bar. Stand on top step and grip side bars with back of hands facing outwards. Slowly lower body until arms are fully extended. Your knees are bent. Pull yourself back up to starting position and hold position briefly. Repeat until a full movement is no longer possible.

Negative version:
Just do first part of exercise, i.e. lower body into extended position. This movement should take about ten seconds. Then climb back up and repeat until a full movement is no longer possible.
You can increase the load further by using the belt.

Important: Make sure that elbows do not move forward during exercise. Your hip remains straight.