Removing old decals on a motor home

I started out with the heat gun, then went down to a hair dryer. The problem I had was, it just left a lot of glue behind which was a bigger job to get off using Goo-Gone. What I wound up doing was using one of those razor blade type scrappers and got under the decal, and very slowly, and with very small scrapes you can get a lot more off. Just becarefull not in a big hurry.