I'm not sure how big your snake is so you may need a bigger container, but here's what I did the first time my snake had a bad shed.

My chinese place delivers food in these small dishes with lock on lids. I filled that with about half an inch of warm water(Not Hot!) and put a washcloth inside. Then i added the snake and let her sit there for a while (10-15 minutes).

In my case, she was having trouble starting the shed at her head, but it was falling off her stomach from her moving around. So I took the washcloth and gently began to kind of peel the shed back(basically just pressing it against the little piece that was shedding on her nose and letting her do the rest). Granted that my snake is not head shy at all and that really helped here, but you may be able to do the same.

Once she got it off her head, I just heald the wash cloth around her and let her slide through and it took it right off.

The trick is that you're helping the snake shed... not doing it for them. Don't force the peel, instead just give them the oppourtunity to shed with help.