The best tool to use with "decals" is a blow dryer. They don't get
*too* hot, as do heaters intended for electronics use, but just nice and toasty at the usual 1.500 watts. Once everything's nicely warmed, just peel it away from the surface.
This also works, by the way, in dealing with the advertising that some Dealers are addicted to slopping onto the backs of the cars they sell, or with any factory insignia you might not like. I noticed in Germany a few years ago that virtually none of the "performance" oriented cars have any info other than the make displayed on the back. Friend Juergen S. tells me that one learns to quickly count exhaust pipes before seeing what the other guy can/will do on the road.
bob noble Reno, NV, USA