The first step is to prepare materials, Galaxy S21/S21+, HD/privacy protective film, a special easy-install tray, and bubble scraper, and a screen cleaning tool. Secondly, open the cleaning bag, use an alcohol prep pad to wipe the screen, use a dry rag to clean the screen, and finally use a dust absorber to absorb the dust on the screen. Thirdly, take out the protective film from the frosted bag, then pull the label ① to tear off the back film, find the "UP" of the tray, align the position of the lens opening with the top two positioning points, and the bottom with the two positioning points. Finally, cover the fixed screen tray on the cleaned Galaxy S21/S21+, and then use the scraper to push it from the bottom to the top. If there are tiny bubbles, use the scraper to remove them. After confirming that there are no air bubbles, remove the front green protective film, and re-scan the fingerprint. Or you can watch the installation video.