There are probably several varieties of stickers beng used, but I have had good luck using a hair dryer to heat the sticker.
This softens the adhesive enough to allow the sticker to be removed. Usually I have been able to get the sticker and most of the adhesive off that way. A couple of times I have had to use something to remove a small amount of adhesive that remains. Several products will do that. WD40, Goo-Gone, Sticker Off, and I have used a cleaner/wax with some success.
Charles