how to remove shower tap
Normally turning the pipe anti clockwise will unscrew the pipe from the threaded elbow in the wall. Looking at your top photo I would bet that is the correct advice but the 2nd photo looks like the valve, you will need to remove the cover it may be held in place with a set screw or grub screw if it doesn’t unscrew. then you should be able to remove the surround or back splash I would make that corner is sealed with your new work as that is a place where a lot of water can enter the wall and cause rot.