As Eric said, use Mineral Oil, or even vegetable oil. It takes awhile; but, it softens and loosens the glue, enabling the animal to wriggle loose. Once the snake is off, normal movement will coat the sticky parts of it's body with dust/debris and once that's happened, it will be able to move normally. Then, the next time it sheds it's skin, it'll be rid of it all.
Also, open the trap and secure it down. It's as easy as using a staple gun to hold it firmly to a board. That way, as the snake struggles to get unstuck, it can get some leverage to pull away from the sticky surface. Make sure that you cover the entire sticky surface with the oil so that the snake does not just get itself more stuck.
So sad. Is he beyond help?
