Turn off the water supply
Remove the old shower components
Inspect the plumbing and wall area
Install or replace the shower valve
Connect the hot and cold water lines
Install the shower pan or base if needed
Install the shower drain
Install wall backer board or waterproofing
Apply waterproof membrane or sealant
Install shower walls or tile
Install the showerhead arm and showerhead
Install the shower trim and controls
Seal joints and edges with caulk
Turn the water supply back on
Test for leaks
Clean up the work area