removing the protective film that normally gets removed after installation. each time I tried to remove the film on top, the protector came right off of the watch (first cleaned with windex), so being persistent I tried a couple more times and no go, so I stripped off the top film, slapped the protector back down and voila, it's stuck on just fine. If u do this be sure to round (well, a straight cut actually) the corners. Clean watch surface, good lighting, sharp scissors, dust free area, etc...