I have had mine done, got a guy who works for leakpro to do it, charged me $75.00 cash for the labor. I didn't use the gbody ones though. Do you know who the manufacturer is for the ones Gbody is selling?
If I recall after removing the old ones he used a cleaner to remove any old adhesive. I was lucky there was no rust anywhere and the weather strip came off really well. You also need adhesive to install the new weather stripping, it was from 3M, you can buy it any auto body shop supply store or "A1 auto" if you do a search. This was a not a job I would have done myself, even the pro got messy but the end product was excellent.
I did the doors myself, they were a breeze. There was a how to posted a while ago. I tired searching for you so I could attach a link but I had no luck.