Removing old decals on a motor home

If they are just vinyl decals, you should be able to heat them up with a heat gun and gently peel them off. If that doesent work the Vinyl sigh industry sells special spray on liquids that help with the removal as well as attachments for a 4.5 " grinder that will help remove the stickers.

https://www.amazon.com/Whizzy-Wheel-Pinstripe-Rubber-Eraser/dp/B00FJF0O2K

If on glass, use a razor blade to scrape off.