3. Make a cardboard template with for the plumbing wall. Measure from the top of the tub to the top of the shower area and create the template with those dimensions. Cut out holes for the showerhead, the control knob, the drain and the spout. Add notes so that you'll know which edges face the back wall, the ceiling and the tub (figure B).4. Lay the template over the existing wall to make sure the cut-outs line up. Once it's correct, lay the template over the piece of the surround for the plumbing wall. Use a utility knife or jigsaw to cut out the holes
5. Remove the template. Install the surround with double-sided tape and caulk.