Bob ...I had 3m film put on my coach the day after we bought it. Mine got to looking bad enough (but not like a knife fight!!) that I decided to peel it off. Basically, the removal method is heat, patience, sore fingers, etc. I got some stuff called "Vinyl Off" online. Rather than heating with a hair dryer or heat gun, my technique was to let the summer sun heat it up, then work it. The recommended method is to pull it in strips an inch or so wide, and work small areas and small pieces. Much of mine came off in smaller pieces as it was scratched and marred like you describe. In some places, it held together in larger pieces.
Whether or not you incur any paint damage during removal probably depends on how well cured the paint was when it was put on. I did loose some hand-sized and larger patches of clearcoat on a light colored paint area. I believe that area was repainted shortly before we bought the coach (due to overspray evidence and some other things ...it had been a dealer show coach). I lost only a very small dot of paint down to metal ...that appeared to be another touch-up area.
I still have some to remove ...waiting for those hot summer days!!!
I also had some film applied just under the engine compartment opening to keep scratches by mechanics, etc to a minimum, and the factory applied come under the entry door above the step. Those two other areas are fine. I guess the front gets more weathering and sun exposure and wear from scrubbing bugs, etc. When I have mine completely off, and get whatever paint repair I might need, I definitely will NOT replace the film. I believe paint and touch-up will be less expensive AND look better for the long run.
Paul (KE5LXU) ...was fulltimin', now parttimin'
'03 Winnebago UA 40e / '05 Honda Odyssey toad