Lighter fluid is what you need, pick a corner a bit to get it started then pour on the lighter fluid, then peel a bit more, then more fluid. Keep doing it until the decal is off. Go slowly and don't start pulling too hard otherwise the decal may rip.
The fluid disolves the adhesive on the back of the decal.
Don't smoke a cigarette whilst doing it though,
Oh yeah, your fingers will go white also.
