It's very easy to replace a single tile (or multiple tiles) that's become damaged after installation. An oscillating saw makes quick work of it.
Simply cut the tile along the grout lines and through the backer board to isolate the tile. Be careful about cutting too deep into the wall surface. You can use painter's tape to cover the adjacent tiles to reduce the chance of damage to those tiles. It may be helpful to first dig out the grout to make sure there are no staples in the grout channel - if there are, cut around them or pry them out. Carefully remove the tile out of its place. Cut a new tile away from a spare sheet and attach into the previous tile's space. You will have to use adhesive to attach the tile since there will not be enough grout channel to use staples. Let the adhesive cure a bit before regrouting. We've made a video about replacing a tile - check it out on our Resources page.
*We do not recommend or endorse specific manufacturer's tools. Use what is most convenient for you.