First of all, prepare your body for the exercise. Spend a few minutes to warm it up. Place the pin on a setting that enables you to go for 12-15 repetitions. Increase the weight, if the exercise becomes hard to do.
After placing the pin, move forward and stand on the step, grabbing the handles firmly with both hands. This will automatically increases the involvement of the arms and wrist muscles.
There is no need to be hurry. Lift one knee at a time, and place it on the padded knee rest. Carefully place your second knee on the pad, and your entire body weight will be transferred to the knee rest. This is the time to pull hard to lower the knee slowly.
Keep pulling up as far as possible. Make sure that your back remains straight. In the meantime, you should ensure that the arm muscles are not used more than necessary.
The first rep will be completed when your arms will be fully extended. Repeat this for at least 12 to 15 times. The best thing is to continue exercises, until you feel exhausted. Dismount yourself, and let the knee pad return to its original position.