Here's what you have to do:
Wrap the heel of your right foot around the heel of his left foot. Then drop to the ground. While you are dropping to the ground, use your left foot to kick to front of his left foot (slightly above where you wrapped your right heel). If you do this correctly you will have him in a hold where you can force him to the ground. Do this, but don't let go of his leg. Now using your hands take control of his left and right leg (once you have his left leg in grip with your hand you can take your feet off). Now stand up and pull both his feet with you so his legs are pointing upward but the rest of his body remains flat. Now, wrap your left leg through his legs (towards his face) and then plant it on the ground to the right (your right) of his torso. With his right leg in your left hand, thread his right leg over his left leg to form an X. Grab his left leg with your left hand and grab his right leg with your right hand. Push down on his right leg. Now, pivoting on your left foot, swing your right leg around so his body rotates and he is now on his belly. Pushing down on his legs with your hands, lean back to apply pressure on his thighs and lower back.