Thanks for all the replies guys!
There was no blood, thankfully he wasn't cut at all. I was so scared using the box cutter, but it seemed like the quickest way to get him out and he'd been in there for awhile. I cut tiny pieces away from his body and then chipped them away. Eventually the hole was large enough for me to get him out with no pressure!
The skin that came off was like flakes of scales.. I think from him trying to pull backwards out of there. That's what made me so scared to try to force him out backward.. yet in my moment of panic i couldn't think of better approaches. I'm glad i didn't try to pull him out though, it would have just caused more damage.
This is what he looked like directly after being free. You can see the kind of flakey skin/scale loss.
The scariest part was this neck thing. I set up a fresh tub for him with no substrate and by the time I had him settled into it, the swelling was gone thankfully.
Here are some pictures of him that I just took. His scales look a little stretched out still, but for the most part I think he looks good considering his ordeal.
The most affected area
Underside looks pretty normal though
I will wait a few more days - I've been disturbing him as little as possible - to offer a small meal and I'll coat it with Nutribac just in case.
So far, so good though. Thanks again for all of the support and well wishes! I'm sure that's part of what helped him pull through.
As far as the tubs go.. I should at least email the people at Animal Plastics and let them know what happened. They recommended these new tubs to me, and I told them I'd let them know how they worked. At first everything was fine, but I can't give them a perfect report anymore. It's not AP's fault.. more Sterilite. I've taped over the holes in all of the remaining tubs. It seems like a snake will just glide over the hole if its firmly taped over, and even if they did nudge against it, it would take some doing to uncover the hole. I'm hoping that snakes that haven't discovered the holes yet never will.
I'll also ask if they can recomend another tub brand to me, but I'm afraid I'll have to get a whole new rack. It took me a LONG time to finally find the bin that fit with my rack. This is the only thing Sterilite currently makes that is compatible. *sigh*!