Turn off the water supply to the tub
Open the faucet to relieve pressure and drain remaining water
Remove the faucet handle
Remove the trim plate or escutcheon
Unscrew and remove the old tub faucet spout or valve components
Inspect the plumbing connections and clean the area
Install the new faucet parts or replacement spout
Tighten all fittings securely
Reinstall the trim plate and handle
Turn the water supply back on
Test the faucet for leaks and proper operation