If you want to do it yourself, the first thing to do is check to see if all the bolts will come out without breaking. If you can loosen all the body bolts by yourself without breaking them, you are already way ahead of the game. If one feels like it is stuck - stop right there. Soak it with some rust penetrant (gotta get it from the top-you may have to drill a small hole right over it in the trunk floor, or the rocker panel, or wherever it is) and let it soak for a day or two. You may get lucky and get it out.
After that, the bumpers have to come off. Both of them. Then it's just a matter of lifting the body up one side at a time with a good jack and some 2x4's.
The aftermarket polyurethane body mounts are great.
A body shop will charge by the hour to do this job. If it is a pain in the arse due to rusty bolts, it could get expensive.