Replace Loose Floor Tile. Mark entire perimeter of problem areas with chalk tape or similar. Place a dust sheet around the work area.
If the adjoining ones are also loose scrape out the grout around them and then carefully pry them out too. Pry the tiles off of the wall with a hammer and flat chisel. Lift out the loose tile with a putty knife.
Scrape the underside of the tiles and the underlayment to remove old mastic then put fresh mastic on the underlayment and press the tiles.
When all of the grout is removed from around the broken tile cover it with a drop cloth. Heating the tile with a warm iron will loosen any adhesive that might still be holding the tile. Set the tile aside. When all of the grout is removed from around the broken tile cover it with a drop cloth.