
On knees and elbows, protecting the neck.
When your opponent turtles up, they have stopped your pass but given you a chance at their back. From the top of turtle you can sink hooks for a back take, roll them with the crucifix, or attack the neck with the clock choke.
Stay heavy on their back and stay behind their shoulder line so they can't sit out or catch a leg. Break down their base with a hook or a hip push, and move to the back the moment they open up.