So a plumber mounted the valve body of an Ashfield assy upside down (tub outlet facing up) (dumb f*&ker!!! :furious::furious

, and well needless to say, water runs out the shower head when I open the faucet. It is also leaking, and I'm about to check the seals, etc in the assy.
The (brick) wall has been closed up around the connections, and the wall is tiled off - so I cannot access the assy to turn it right side up without cutting tiles:furious::furious::furious:. I can still access the front of the assy, though. Is there any way the valve internals can be modified (turned) to fix this? Thanks.