It’s not easy or fun. I usually start with a knife at the corner to get it started (careful not to scratch) then pull the whole sheet off. It should leave a residue on the glass, get it nice and soapy, then scrape. After that, you’re now ready to proceed with typical cleaning.—If it’s old tint or on sunny side windows, it could be baked (just the way I describe it) meaning that when you try to pull the whole sheet, it will crack and not come in one piece. This requires a bit more work, but you still can scrape it off. (When I mention scraping, always remember your usual risks of using a scraper) I recommend at least double pricing. It can seem high but it’s a one time fee for extra work. Hope this is helpful Rowdy, good luck man!