Get a razor blade to pick the edge of the sticker up, and then peel it off. Clean off the residue with a paper towel and WD40.
edit:
Originally Posted by DragonMistress
that's the advantage Googone has...it takes patience, but you can't damage your paint with it.
Considering that stuff turned the black paint on my old bike to charcoal gray, I'm going to have to go ahead and disagree with you there.