The cracked or split tiles must be carefully removed without damaging the neighboring. First you need to remove the grout from the seams and some sharp object (for example, with a nail or spatula) to scatter the dried gluing solution around the entire perimeter of the tiles from the seam. This is time -consuming, so you need to stock up on. Then, the angles of the tiles removed and slowly continue to chop the tile in small pieces with a chisel with a chisel. Next, you need to install a new tile on a silicone or on a solution, having previously removed the old from the surface of the wall or floor.