Installing a porcelain soap dish on a tiled wall involves removing a few tiles from the wall to create space for the dish and attaching the dish onto the wall with a tile adhesive. Sealing the gap between the dish and the adjacent tiles completes the process.
To remove tiles from the wall, start by selecting a suitable location on the wall. Hold the dish against the location, and draw along the dish edge with a pencil. Gouge out the mortar between the tiles found inside the marked line with a grout saw, taking care to protect your eyes with safety goggles. Using a nail and a hammer, make holes in the tiles within the marked location, taking care not to drive the nail past the back of the tiles. Cut the tiles along the hole with a drill, and pry the tiles away using a chisel and a hammer.
Before installing the dish in place, remove any mortar remnants from the wall with a grinding wheel. Apply a 1/4-inch layer of tile adhesive over the place with a putty knife. Attach the dish over the wall, use a level to position the dish and reinforce the attachment by taping the dish in place. Allow the adhesive to dry, and peel off the tape. Finally, apply premixed grout to seal the gap around the dish, and remove any excess grout by wiping.