1.) Get a mouth expander. There's nothing quite like having the roof of your mouth lowered a half-inch by a thick piece of inflexible plastic. Then, of course, you have to turn the little wheel twice each night, and be able to feel the pressure in the bones in the roof of your mouth. For the first couple days you will be forced to spit every three minutes or be doomed to have drool hanging out of the corners of your mouth, something like those dogs they show in movies.
Every time you swallow, you'll about scream from the pain on your teeth, and any food that gets stuck between the plastic and the roof of your mouth will be inaccessible for no less than a month or so, until the space between the two plastic plates is large enough for a sharp pipe cleaner to be stuck in between and force any lodged objects out.
Try not to impale the roof of your mouth, and try not to choke on dislodged objects, especially chunks of meat. It's not fun, and may induce vomiting. Especially old chunks.
I guarantee you will live on a diet of oatmeal for the duration. I did it.
2.) Get rubber bands. This is nowhere NEAR as effective as the expander, but is still worth considering. Expect to not be able to yawn, laugh, talk, or eat without giving your jaw muscles a damn good workout. Also be prepared for an experience in whiplash if you open too wide. Oh the lovely combination of pizza and rubber... Oh, and you have to break EVERYTHING into pieces before eating it.
Hmm, this also could have been titled "How to take the fun out of eating"...