Are you guys sure there isn't a solution that doesn't involve partial or total destruction?
I want it disconnected without damaging anything. All I want to do is insert a two way valve and put a flexible hose and shower head on as well as the existing showerhead. Yes I didn't say that earlier, but I didn't want to complicate the story.
(And when I finish renting and move on, to reverse the process! So I need the existing showerhead without a scratch on it.)
It cannot be corroded on - this property doesn't even show on Google Earth - it is about two years old - max.
Here's what it looks like - quite standard.