Lay a large bath towel on a flat surface and place the mirror on top of the towel so it doesn't break.
Remove the area that needs new silvering, or the entire face of the mirror, with the safe scraper.
Spread the chemical remover over the silver to be removed, if you choose not to scrape it. Allow the chemicals to remain on the glass for 15 minutes, then remove with a microfiber cloth.
Lay the new mirror within the frame or the clamps of the old silvering. Place the frame front or move the clamps over the new silvering and adjust everything into place.
Move anything that's supposed to hold the glass in place to the correct position. For example, if there are wooden pieces make sure they're holding the glass by placing them horizontally across the mirror.