I have just stuck them over the old sheet vinyl in our old house. Just make sure the floor is clean and dry first. It would be better to set toilet over the tile but I just cut the tile to fit around the toilet. I used the the backing paper from a few of the first tiles I set to create a template. Place the corner of the paper so that it aligns with the adjoining tile. Smooth it against the base of the toilet, then trace or cut the curve around the toilet. Use that paper as a pattern to cut the tile to fit. then a little bead of Silicone caulk can seal the seem. Heavy duty Fiskar scissors work to cut the curve.
Peel and stick tiles are a great inexpensive fix for a bathroom redo! If you have ONE layer of linoleum you can install them right over the linoleum. If you are installing them over a old linoleum floor you can roll on a coat or two of pre adhesive primer to assure your tiles will stick well and stay in place. It is a liquid in a bottle and you can use a regular paint roller to apply. It dries quickly. The boxes of peel and stick tile usually have good installation instructions so read EVERYTHING carefully. I would consider removing the toilet and vanity before tiling. You would need to buy a new wax ring or two to put your toilet back in place and I would run a bead of clear bathroom caulking around the bottom of the toilet once you have everything done. Make sure you have the proper tools. A ruler and a good utility knife with extra blades are necessary.
Hey Brenda! Peel and stick tile is pretty easy to install, as the name suggests, just peel and stick! Here's a video showing exactly how easy it is! The main thing to worry about is getting the surface prepared correctly so your tiles stick! Here's a video showing exactly how easy it is!
Here's how we did ours: