Cider,
This is not difficult, once you have done it, but you should really have someone show you this procedure. If done incorrectly you cold injure the snake. How large is the snake? usaully anything over 17"-19" is to big to "pop". I'm not saying it can't be done, I just find it safer to use a probe, which can be just as dangerous in the wrong hands. Both these procedures are described in The Corn Snake Manual--If you have not bought it yet- I highly recomend it. Best of Luck!