Stand directly behind your opponent.
Wrap your left arm around your opponent's neck from behind. Your left elbow should point in the same direction as his throat (away from the windpipe).
Grab your right bicep with your left hand. This is the first part of how the pressure is applied.
Wrap your right arm around the back of your opponent's head.
Push the back of your opponent's head forward into your front arm. This will squeeze his neck and cut off the blood flow to his brain.