The body mount bushings (rubber) are held on by an upper and a lower metal sleeve that goes through the frame. As Blade stated, it's often very hard to separate them, since they are pressed together. The lower sleeve has a small "lip" that helps keep it in place. One way to separate them (other than cutting apart) is to remove the long bolt, then thread it back in about 1/2" into the lower washer-nut-sleeve assembly. Use a punch and large hammer to knock the lower sleeve down and apart from the upper. USe alot of penetrating oil, and the biggest hammer/sledge you can handle. You may damage the threads on the bolt or the nut, but you may be able to re-tap them. I buggered up two bolts out of eight. If you have a bushing knocker set, that may work, too.
The front mounts under the radiator core support are different in that the bolt threads into the sleeves. These are more often rusted together, and cannot be hammered apart. I removed one by cutting away the rubber, and grabbing the upper sleeve with large Vise-grip pliers while turning the bolt. The other had to be cut off with a torch.
I replaced my body bushings with poly's from Daystar. I do have pics of the mounts and bushings at superford.org, JSM84