Adjust the padding so that when you are seated it is pushing firmly on the top of your quads, approximately in the middle of the thigh. Stand to grab the bar with an overhand grip and space your hands at roughly shoulder width apart. Holding the bar, lower yourself into the seat.
Start by pulling the bar towards your middle chest region. Once the bar has been lowered to a point just before your chest, slowly extend your arms to the start position. Your elbows should be going towards the back of your hips. Try to maintain a slight and steady lean backwards throughout the whole exercise. Repeat for the desired amount of repetitions then slowly raise yourself until the weight is caught.
Avoid relying on excessive momentum to pull the weight.
Fitness for all, for life.