I want to change the shower and tub fixtures. The old shower head has a ball valve so I will need to get back behind the tile to do this. There is a linen closed adjacent and should provide access. Do I just cut the sheet rock to see what is behind there? This will be a new plumbing experience for me. I have done fine replacing lines to other projects and have replaced the bathroom and kitchen sink fixtures without problems. My spouse can do everything EXCEPT plumbing (as there is always a leak). Does anyone have any tips before I dive in to this project?