The internet is full of amazingly bad advice on almost everything you can imagine. When removing tint, the absolute best way to do it is with a steamer, heating the glue, and pulling off the film carefully.
I recently removed the tint from my '03 Evo, and it must have been on there for a LONG time, because it came off really badly. On the back door windows, I removed the film and then used the steam gun to heat up the remaining glue on the window and scraped it off with a razor blade. This technique works very well, as the steam helps ball up the glue into clumps.
On the rear window, the film came off leaving most of the residue behind, but you can not scrape the remainder off with a razor because of the defroster lines. I was quite upset with the amount of residue left, and tried a few products. First I simply tried Primis window cleaner, and this did absolutely nothing. Next I tried Goo Gone, and this again, did nothing but make my window more oily.
I then went to my rack of chemicals, and found a container of 91% Isopropyl alcohol I use when I repair Xbox 360’s, so I tried that out and it worked like a charm! I just soaked a paper towel in the alcohol, and upon rubbing it on the window, it literally dissolves all of the residue, just leaving a small film behind. After I did this to the whole window, I hit it with some window cleaner, and it looks as good as new. In the future when I remove tint for people, I won’t even bother scraping the residue off or being careful, it’s faster just to use the 91% alcohol.
Goo gone did nothing for me either. I used carb cleaner to get mine off, and it worked wonders. 2 things though. 1. keep using clean parts of the towel or you’ll just drag half dissolved sticky residue across the window. Also don’t spray the carb cleaner directly on the window, it’s potent stuff you don’t want to get on your door moldings and such so spray it into the towel then wipe the window 2. USE MICROFIBER towels. Regular towels leave behind sooooo much crap. Microfiber catchs everythings.
After cleaning the goo off, thouroughly reclean with glass cleaner.
Super high grit steel wool works, like the #00000 I think. I’ve used it in the past, soak it with some sort of cleaner and let it do the rest. Doesn’t scratch the windows.
