Wall-mounted toilets can make the most of a small space in a bathroom. These toilets usually have their tanks for flushing concealed in a wall space. The toilet bowl itself mounts on the plumbing that sticks out of the wall, which also supports the toilet. You can change the seats on these types of toilets fairly easily.
Turn off the water supply for the wall mount toilet. Most wall mount toilets have a water tank hidden within the wall cavity. How you turn off the water supply will depend on the type of wall tank you have installed. Most wall mount toilets will have some type of water supply shut-off valve installed near the tank. Rotate the handle to the "off" position to cut the water supply.
Use a container to remove any water left inside the toilet bowl. Insert an old towel into the bowl and into the drain to soak up any water you may have missed.
Place another towel on the floor underneath the bowl to catch any excess water. Locate the two screw covers securing the toilet bowl to the wall. Remove the covers with a screwdriver. Loosen the screws.
Run a sharp utility knife around the caulk between the bowl and the wall. Pull the toilet bowl forward and off the plumbing pipes. Wipe up any water that spills.
Apply silicone grease to the plumbing pipes protruding from the wall. Turn the bowl around so you can see the rear face. Insert a tube of silicone caulk into your caulk gun and trim off the end. Apply silicone caulk to the rear face of the toilet bowl. Lift up the new wall-mount toilet bowl and set it on the plumbing pipes. Slide the toilet back until it meets the wall.
Insert the toilet bowl screws through the bowl and into the wall. Tighten with a screwdriver. Press the screw caps back into place.
Loosen the nuts on the underside of toilet seat where they protrude beneath the bowl with an adjustable wrench of pair of pliers.
Pull the seat off the toilet. Replace with a new one. Secure by fastening the screws to the seat screws on the underside of the bowl.
It is also possible to replace the seat before mounting the toilet on the wall.