is your refereeing the body as the frame then what you will have to do is use the better frame of the two .and remove the 4 cylinder engine mounts ,if u plan to use your 6 cylinder use those mounts. swap in the driveline with the electrical harness. Put Everything else together.I would be more descriptive but its really a lot of info.But how hard is the body swap is not the question , the question is how much time you have on your hands, if your schedule works around the weather, and how much knoweldge you have on cars. right now i am swapping the tub and driveline from my old jeep onto a new frame, personally i think 1 jeep was enough work but to take 2 apart good luck. You will also need a engine crane and a couple of helping hands. and last but not least some mula .Not to hyjack your thread but if you want to see some pics of the process you can check Frame Removal thread and you can check Doc's photobucket album.