I usually warm up the sticker with a hair dryer. If it's a foil sticker heat first and any residue is removed by using Kroil lubricant on a rag. If a paper style sticker, soak the sticker with Kroil, let set for 15-20 min, peel sticker off and use Kroil on a rag to remove any remaining adhesive. WD-40(water dispersant formula #40)oil can also work.
Soman2
The other Rodney