How to Remove Old Window Film

You'll need black trash bags, household ammonia, fine steel wool, a razor scraper, glass cleaner and a few hours.

1. Cut a trash bag to cover the window and spray ammonia on the outside of the film (inside of the glass).
2. Stick the bag over the wet film and leave the car in the sun for an hour or so; the heat softens the adhesive.
3. Peel the film from a corner, keeping it wet with ammonia.
4. Remove leftover adhesive with ammonia and fine steel wool, avoiding defroster lines, then clean the glass.

Work in a ventilated area and protect the interior from drips.