They sell a spray at pep boys that removes stickers and doesn't harm your paint, you can just spray it on while your car is wet and also, there's this little rubber thing that's similar to the rubber thing on squeegees that is used to scrape the stickers off of your car.

For the tint. I'd go and buy tint remover. It's compiled of a tint remover solution that you mix with soap and water. Spray your solution all over the sticker and use the same rubber scraper thing to scrape the stickers off of your tint. Be very careful so that you don't scrape off any tint or scratch it.