The quickest way is to use a commercial mastic remover.
Taking tiles off stud wall.
Tiles installed with thinset or another tile adhesive often require more work to remove them.
Try to locate a loose tile.
Wedge the end of a putty knife beneath the bottom of a tile and gently pry outward.
Work slowly and at about a 45 degree.
Scraping away grout between the tiles is the first step in removing them.
Once the tile is down take a 5 in 1 tool and scrapper to remove any excess grout.
The method used to attach the tiles to the wall affects the way the tiles come off.
Follow the directions on the bottle for application.
How to remove bathroom tile without damaging the plaster walls step 1.
Slide a putty knife or plaster spatula behind the tile getting as much of the blade behind the tile as you.
Chisel tiles away from the wall.
If it is how it is repaired depends on how the wall is constructed.
You may be lucky and the tiles will come off without damaging the wall too much.
This approach should let you save more of your tiles for reuse unless the tiles are.
Usually the remover is applied to the remaining clumps of adhesive with a rag brush or sponge then left to sit for a few minutes.
This can also be done with the addition of a light sander using fine grade sandpaper.
Cut away the grout surrounding the tile or tiles that you want to remove.
If the wall is a proper stud wall then the new plasterboard can be fitted over the original studding.
Remove the grout first.
Dissolve the tile adhesive which is also called mastic.
Break the tile if necessary.