>>933063
What's behind that wall? You could just cut behind, and install an acces panel. And get the opinion of another plumber just in case.

>>933072
This, take the drywall down behind it.
That is unless your faucet faces the outside wall then you are screwed.

>>933063
technically you dont have to remove the whole wall of tile, but he probably wants to keep the color/ aged look of the tile the same.

removing and installing a new shower diverter is doable for a novice /diy/. if you could get to it from a drywall angle like >>933072 suggests it would be a lot easier

removing and installing new tile is probably too hard. removing the current tiles and drywall and prepping the new surface for tiles after you fix it is not trivial.

Wouldn't need to break the tile that is there. Use a multi tool or Dremel and cut the wall out around the grout line, do what you need to do to the plumbing , remove wall and adhesive off old tile. Patch wall and replace tile

>>933063
I'm a bit confused by the plumber wanting a small section of the wall removed in order to do the repair unless the whole diverter valve unit is somehow at fault. If a merely dripping faucet is just the problem, a replacement cartridge should (hopefully) solve the issue. The old cartridge pulls out at the front and the new one is pushed back in place. A retaining pin (depending upon the manufacturer) is usually used to keep it in place.

If it were me, I'd try fixing it myself with a replacement cartridge and see what happens. It would be quite a pain in the ass to remove a section of your wall and then later find out it was never necessary to do. You'll possibly void your warranty if you did this, though. I'm not saying your plumber is wrong either, but it just seems odd to me.

>>933063
>cartridge replacement
https://www.youtube.com/watch?v=Lg5CdQgzscI