If you've got a ceramic tile wall or floor and one or more of the tiles is askew — either crooked alongside the other tiles or raised out of the tile surface on one edge — it means it wasn't installed right to begin with. You don't have to live with it. You can extract that tile intact using a chisel and grout saw (a square carbide blade on a handle) and then re-set it correctly. Take your time extracting the tile, as you don't want to break it.
Things You'll Need
Thin mortar chisel
Small razor scraper
Dig the grout from the edges of the uneven tile, using your tile saw to break the grout surface and scrape it out, without damaging the tiles.
Hold the tip of your chisel in one of the spaces around the uneven tile, where it meets the wall. Angle the chisel and gently tap it with a hammer. Move the chisel to several points around the tile and repeat, tapping at the line where the tile meets the wall until the tile comes loose and pops out.
Use a razor scraper to remove any remaining mortar from the wall. Get it flat and smooth. Scrape off the back of the extracted tile as well.
Spread tile adhesive over the back of the extracted tile. Press it back into the space, getting the grout lines consistent all around. Lay our flat palm over each grout line to ensure it's flat and even with the surrounding tiles.
Let the adhesive set for eight to 10 hours.
Spread grout over the edges of the tile with your grout float, pressing it into the spaces. Use a damp sponge to wipe the excess grout off the tile surface, leaving it in the spaces.