One

STARTING POSITION: Lie on your back and extend your right leg up in the air. Your thigh should be perpendicular to your torso and your shin parallel to the ground. Think about riding a bike throughout this exercise. 

Two 

Next, lift your right leg two to three inches off the ground, hold for a few seconds, then switch legs. Modify your hands if necessary. 

Three

Make sure your lower back is in a neutral position during the entire exercise. You should be able to touch the outside, lower portion of your back but not all the way through. You can then do the exercise and make sure your back neither presses down or lifts up from your hand. If your back is arching (can move hand all the way through) then maybe start with both hands underneath your lower back to make easier.