To perform the exercise, you would start by placing the stability ball on the ground and getting into a plank position with your hands on the ball and your feet on the ground. Your body should be in a straight line from your head to your heels, with your core muscles engaged to maintain a stable position. 

Then, you would hold this position for a set amount of time, making sure to maintain good posture and avoid letting your hips sag or your back arch. You can increase the difficulty by moving the ball around in a circle, moving diagonally, side to side. All additional movement increase difficulty and therefore increase the force you need to exert to stay balanced and in proper form.

This exercise can be a great way to build core strength and improve your stability and balance. Some potential health benefits of performing the stability ball plank include improved core stability and strength, increased upper body strength, and improved posture.