The thin adhesive strip on the outer edge of the glass protector adheres to the camera LCD. After you handle the protector and test align it over the camera LCD, clean the LCD of all residue and dust, strip the wax paper off the adhesive and line up the protector over the LCD very, very carefully before pressing it into place. The adhesive is tenacious - although it won't harm the LCD in any way - and once pressed into position the protector can't be lifted and repositioned.
The easiest way to remove the GGS protector (if it cracks because of an impact) was suggested a few years ago by another Nikonian. Use some strong dental floss to strip it off, then a bit of softener to remove any adhesive residue. The last time I removed a GGS protector, the adhesive residue rubbed off with very little effort and what remained came off just as easily with a tiny bit of 90% isopropyl alcohol. Took two minutes.