Removal of graphics

I had to buy the eraser wheel on EBay. I used it today, and although it works better than simply using a putty knife, it is still slow going. My decal is straight, about six feet long, and goes from about 7 inches on one end, to about 1 inch on the end other. At the rate I am going, it will probably take six months to take it all off, even if I work at it daily. I only used the eraser wheel about 20 minutes and it already showed signs of wear. I am probably going to need two more eraser wheels. It's like using a giant round eraser. Tomorrow I will try a combination of heat gun, putty knife and eraser wheel. It is best to use a battery powered, variable speed drill with a reverse in order to get at the edges of the decal from different angles, otherwise you have to turn the drill to different hand positions. This will be the last decal I ever remove in my life. From now on, I will mount new stickers over the old stickers.