Shower mixing valve

[One wildfire]

I need to replace mixing valve on shower and the hole that was cut in wall isn’t large enough to remove cartridge as it was designed to be removed . The wall between bedroom and bath will have to be removed to access it from backside. How is wall secured, ours has a TV on bedroom side.

[BayouBiker]

most people just cut the hole a bit bigger. if you mark the decorative cover with some painters tape and make a jig the size yo need to remove the valve, you won't cut too far.

[69SoulShine]

I used this Holesaw. After I fretted over cutting a hole in my shower wall it took less than 30 minutes to be done with the job. If I can answer any questions pm me.