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.

House windows

Home film comes off with heat instead of ammonia and sun. You'll need a hair dryer or a clothes steamer, a razor scraper, soapy water (half a teaspoon of mild soap per quart) and a few cloths.

1. Warm one corner of the film with the hair dryer or steamer for a minute, lift it with a fingernail or the scraper, and peel slowly, keeping the heat moving just ahead of the peel. Pull low and steady; a fast pull leaves the adhesive behind.
2. Spray leftover adhesive with soapy water, let it soak a minute, and scrape it off with the razor scraper held flat. Scrape in one direction and keep the blade off any rubber seal.
3. Wash the glass, then clean it again with glass cleaner before new film goes on.

Static cling film peels off dry. Frosted and decorative films come off the same way as solar film. If the glass has a room-side low-E coating (uncommon; the window label says), use heat and soapy water only, no blade.