I really can't describe it well, but it is something I learned a long time ago. Geni your two arms in the crook of his elbow, do a crunch to bend his arm and try to push it to your feet. When his elbow is bent 90 deg and his forearm is flat to you stomach, swim your arm over his arm to underhook or his opposite lapel. He still has the grip but it is an underhook lapel grab with elbow bent. If you do it correct his hand will be stuck in your armpit leaving him no base on that side. Then it is just a plan b/ whip back type sweep to that side. I would threaten a weak cross collar choke from 1/4 guard and pull him down flat on top of you threaten the sweep as you then mini-stomp to lockdown. Most peoples triceps are not strong enough to keep the arm straight while you use your two arm to push at the elbow.