Deep Half Guard from Back Escape

If someone has your back....

Basics;

Start with Vampire defense so you can grab his choking hand
Whichever side he tries to choke you one grab that wrist with your opposite hand, then swim your adjacent arm up and over your opps arm so his arm is now trapped under yours (in almost a kimura lock)
GET YOUR SHOULDERS TO THE MAT!
Free your legs from his leg on the side you are trying to escape to

From here, your opp is most likely going to give up back control and try to mount you; as he does this he is basically in half guard....all you have to do is pinch your knees around his knee.

As he tries to get on top swim your inside arm under his leg....and scoot your hips under him until you are in deep half guard!
Right away bump your hips up and push him forward towards his hands. As he tries to bring his weight back roll him over and sweep him backwards.