Lots of elbow grease... I've found the flap wheels that go on an angle grinder pretty useful on the chassis where you can get a good surface to work on and dont have to worry about damage.
Body panels I've yet to find anything much better than paint stripper. A pressure cleaner can be used to remove the paint once it's reacted with the paint stripper, this saves some work scraping it off. I am going to get my bulkhead soda/sand blasted but havent yet asked for quotes.
I have found "Citristrip" better than the traditional paint strippers as it is less caustic and stays wet longer.
3M make a wheel that goes in a drill that is designed to strip paint, looks like a round scotchbrite pad. These can be good to clean up stubborn bits of paint but are no easier than stripper on a large surface.
Regards,
Tote

