I found the best way to remove paint from my Dormobile's panels was to apply paint stripper (Bunnings) leave for 15 - 20 minutes, then remove with a wire wheel in a drill or an angle grinder [smilebigeye] It comes off easily and leaves a nice clean surface.
Certainly easier than trying to scrape paint off with a scraper and damaging the surface, just don't be heavy handed and let the wire wheel do the work.

