1. Your starting position is to make sure that your body forms a straight line, take on a push up position when your feet on the ball and arms are completely straight and wider slightly than shoulder width apart.
2. Now roll the ball toward your body without bending your knees, by raising your hips as high as you can.
3. Pause up for a moment, and then return to the starting position by lowering the hips and rolling the ball backward and repeat the movement.
Tips and Advices:
When you push your hips towards the ceiling be careful not to round your lower back.