Ideally, you should have a well-waterproofed shower that would otherwise be trouble-free. If that's the case, then you should be able to do it. Pull out the tile in a larger area than where the problem is. If you have a Schluter type system behind the tile, you can open the wall, fix the problem and use Kerdiband to seal the joints.
Keep in mind that, as a result, you'll get an additional thinner thickness, so you'll have to compensate for it while you put the tile back in place. If you have any other waterproofing membranes, you should probably buy something like Redgard to restore the membrane. If you don't really have a membrane, but only have cementitious backup units (CBU) behind a tile or, even worse, protection against mold, then keep in mind that your current system is not really waterproof, but, on the contrary, absorbs moisture. However, in any of these cases, the main thing is to remove much more tiles than you think are necessary in order not only to reach the leaking pipe, but also to make a sufficiently flat wall of the same material and installation style, and then place the repair tile on top. We recommend using a glued patch to repair holes in waterproof items, as seams would compromise waterproofness.
The first involves removing all the tiles from the shower to repair the leaking or damaged waterproofing membrane and replacing them with new tiles. Black areas = Black areas should be repaired with the help of a waterproof patch or given to a professional repair service specialized in repairing waterproof garments. There are some situations in which a patch is useless, for example, when it is placed over a joint with bulky seams or when the tear is too large to cover with a patch. Noso patches is a brand that makes high-quality patches that are waterproof and last in the washing machine.
