Locate the edge of the plastic protective sheet. It may be flush with the edge of the brass door plate, or it may be a fraction of an inch from the edge.
Tease the edge of the plastic loose with your fingernail. Gently scratch the plastic, to rough it up, and tease loose enough of the edge to grasp with your finger and thumb.
Move along the edge of the plastic with your fingernail, scraping the edge of the plastic so it crumples up and pulls away from the brass door plate, just enough to grab with your fingers.
Grasp the plastic cover, using your fingertips and thumbs. Position your hands about one-fourth of the way from each side of the top edge of the brass door plate.
Peel the plastic from the brass door plate. Keep your hands parallel to the brass door plate as you peel, to minimize the possibility of the plastic tearing before it is fully removed.