Score a line across the paint to mark where you want to stop scraping. This is particularly important if you are scraping paint off a surface that touches another painted surface. For example, if you are scraping paint off of a glass window and don't want to scrape painted wood trim, score along the edge of the glass to prevent any slip-ups.
Hold the point of the tactical knife at a 30-degree angle to the window and carefully scrape at the paint. Use a slow, short motion to avoid slipping and scratching the glass or causing injury.
Continue to scrape until all the paint is gone. Wipe up any residue with a cloth.