| IF this is factory tint (colored glass and not paste on's) the best method that I have found for any tint or sticker is a hairdryer. Working from top to bottom, heat a small area and start to peel it back.
If this is a aftermarket tint, then it gets a little more tricky and TBH, I would have the dealer that was dumb enough to put a sticker on it remove it. | 
