Remove the Loose Tiles

• A few towels can help prevent shattered tile.towels image by Mary Lane from Fotolia.com
  
  Place a few tiles onto the shower floor to provide a cushion in case any tiles fall while you are working. Cut out the grout from around the loose tiles, using a grout saw. If this does not allow the tiles to fall away from the wall, wedge a scraper under each loose tile and pop it free from the wall. Once all the tiles are off, scrape the old adhesive off the wall or back of the tile.
  
  

Apply New Adhesive

• Fresh tile adhesive is sold ready to go.Fliesenkleber image by pegbes from Fotolia.com
  
  Use a scraper to apply a thin coat of adhesive to the back of each tile. Adhesive can be purchased at a hardware or home improvement store in either a tub or squeeze tube. After spreading the adhesive, scrape a quarter inch clean around the tile's perimeter to ensure the adhesive does not squeeze out into the area where new grout will be applied.
  
  

Set New Tiles in Place

• Make sure the tile is straight when you glue it in place.Tiler replacing wall tile in shower cubicle image by Bryan Clark from Fotolia.com
  
  Press each new tile in place on the wall, centering it within the hole with room for grout all around. The tiles will stick on their own, but you should apply a strip of masking tape over it to ensure it does not move. If the tiles are on the shower ceiling, use two pieces of tape to form an X over each one. Repeat this process for each tile and allow the adhesive to dry overnight.
  
  

Applying Grout

• The grout provides a waterproof seal between tiles.Tiled floor image by Simon Amberly from Fotolia.com
  
  Mix powdered grout with water, following the mixing instructions listed on the bag. You can mix by hand, but a drill mixer will give you a much smoother consistency. Scrape the grout diagonally across the gap around the tile until it is full, then wipe off the excess with a damp rag. Wipe the rag along the grout lines until it is slightly below the surface of the tile. Once the grout has dried, apply a sealer.