Step

Isolate the bad tiles by chipping away the grout around them with a grout scraper or chisel. Smash them one at a time, knocking out the pieces.

Scrape all old adhesive from the wall. Spread the back of each new tile with a thin, even coat of tile adhesive.

Press the tile into place, adjusting the grout spacing, then tap in place with a wood block and hammer.

If you have a leak behind a tile wall, you'll have to remove all the effected tiles and replace the wall behind the tile. This article shows you how to replace a single ceramic wall tile. Adapt the same technique to larger areas, but apply adhesive to the wall, not the tiles. When replacing a section of tiles, plan the opening so it straddles two studs. Then it's easier to patch the wall behind the tiles. Use water resistant drywall or cement backerboard for your wall patch. Don't bother salvaging old tiles; most will break anyway.

Step

Wipe excess adhesive from the surface. Clean out the grout spaces and let dry. Next, apply grout in the grout joints with a grout float, using diagonal passes over the tile. Wipe excess slightly with a damp sponge and let set for 20 minutes. Finally, when grout and tile haze up, wipe area with your damp sponge. Polish with a dry terry cloth towel when dry.