[Jsh]

I have been in the sign & vinyl business for 22 years. The removal depends on the amount of uv abuse the decals have suffered over time. If they are cracked and starting to peel, probably going to come off in many small pieces. If the have just faded, may come off fairly easy. Either way a good heat gun, and adhesive remover to get the glue off after the decal. And yes you will see where the old decals have been. Find local sign shop to look over job for you may be the easiest.