My chick went for about 5 hours now with no progress, not even a hole, just the original crack. No sounds coming any more. I picked the shell away from the crack where a pip was started. Dry membrane! Almost no blood vessels remaining, just 1 visible with about 1 sq inch of membrane exposed. Chick seems to have rolled over and got his back to the air hole. Big air pocket was inside where membrane was away from the shell but all along the side not in the end. See him breathing. How much shell should I remove? Do I need to get a hole near his beak to breathe?