mix amonia and water/tad of soap togeather and spray/soak the glass and then cover the glass with a garbage bag and let it sit in the sun / heat for a good hour and it will peel right off
i used Goo gone automotive, peeled the actual tint off the glue, sprayed that shit all over and let it soak for like 5 mins, used a razor to peel the glue off like gum, worked perfectly
amonia is the fastest way, and the way the profesionals do it. the bags are to keep the amonia from evaporating like the guy said and to keep heat in the glass fromt he sunto soften the adhesive more