The exterior decals, for all that they stay on the cars for years, are not that hard to remove. The same applies to dealership stickers, which many DSMers prefer not to have on their car.
To remove the stickers, usually all that is needed is a little heat from a hair dryer. A heat gun may also be used, but beware - the gun can develop much higher spot temperatures than the hair dryer and could damage the paint. The same can be said of using a cigarette lighter, but both methods can be used successfully with due caution.
After the sticker is hot enough, scrape it off with a plastic tool. You can also try and use fishing line. A little WD-40 or bug n' tar remover with some elbow grease will take off the residue.