Probably razor blade, TLC, and some rubbing compound to finish it up if you want to save the paint. You could also try one of those flapper wheel thingies, I've never had much luck with them myself. If you're painting and don't care about the paint 320 sandpaper on a DA.
I would not use a razor blade if saving the paint is your goal. Use a scraper with a perfect edge, and a heat gun. Use laquer thinner then solvent to clean off the residue once the sticker is gone. Be carefule with the scrapper on hot paint, it will get soft.
i agree... heatguns are your friend, i used them all the time when i worked as a detailer.
get a crappy old credit card, and a heat gun, and the sticker will come right off, then some rubbing alcohol, i cant in good concience recommend anything like acetone or laquer thinner, as ive seen them both wrinkle paint.
laquer thinner on fairly fresh paint is bad, it will remove it. But anything thats hardened for at least a couple months should survive it, just don't let more then a film of it sit on a painted surface for a long time.
I used a true pinstripe eraser in a low-RPM drill to remove my hatch decal. A good automotive supply/bodyshop shld have one. I repainted my car, but if you intent to keep the paint underneath, then you can compound and polish afterwards. Hopefully your paint wont be be too faded. My decal came off like butter... and I reccomend you remove your lock cylinder, which is a 2 minute job itself.
Heat gun, you can pick one up at a auto or hobby shop and go slow, heating each section and slowley peeling, this helps get most of the gunk off. I used paint polish cleaner (the stuff for getting sap off your paint) and then waxed it, came out just find and didnt take too long