Bad shed. Very bad shed.

Wrinkles are normal, it shows he's in shed. Since everything is working, I'd wait it out until tonight or tomorrow morning. See if any more comes off. If not, I'd try giving him a 30min bath, then letting him move through a damp cloth.
Then wait again see if he gets it off by the morning after.

When my BPs used to have bad sheds all the time I would soak them and they'd take nice long drinks. Snakes that don't like water probably won't drink though.

The wrinkles are normal when a snake has a bad shed. Once you get all the old skin off, the wrinkles will go away.

Maybe you could make him a humid hide and see if that prevents the bad sheds? It could also help him now.

Humid hide = a container(rubbermaid style) with a small entrance, filled halfway with moistened moss type substrate. When the snake is ready to shed he can go into it, to hydrate and rub in the moss.

I figure it couldn't hurt, and I use them on the geckos and on the occasional snake before I got everyone in the racks. Of course, Florida is super high humidity anyway. I hope he finishes shedding with the soaking.