I am fairly new to plumbing so bear with me. My problems is I am trying to change/modify my showerhead supply pipe so that I can use a more modern showerhead on it. Currently the pipe that comes from the wall protrudes out about 2-3in. and has a male threaded end on it. I have attached two pictures below. The problem is that the, unless I do some weird Frankenstein action with different connectors, I can't get a normal shower arm or showerhead on the pipe. The shower unit is a one-piece fiberglass deal so getting behind it is not really an option. Lastly the pipe can be pulled out (1-2 inches) and pushed back into the wall (1-2in.) as well, although I am not sure what stresses this places on the other end of the pipe. My plan is to pull the pipe out as much as I safely can, cut the threaded section off and put on a female threaded fitting. Next, I'd like to have the copper pipe and fitting sit behind the shower wall, like I think most modern showers are. The problem is that hole in the shower that the pipe comes through is so narrow that it wouldn't clear the fitting, so plan is to use a hole saw to cut the fiberglass and to give the pipe about .25 inches of clearance all around it. My question is...does this even make sense? Is there a better way to do this? Will it even work, does the copper pipe need to be braced or supported behind the shower wall? Should I call a plumber for this, and how much might I expect to pay? Any tips of suggestions would be appreciated. Thanks. The supply pipe coming from the wall. Standard shower extension arm.