Turn off the water supply to the shower
Plug the drain to prevent losing small parts
Remove the handle screw, if present
Pull the old handle straight off the valve stem
Remove the escutcheon plate, if needed
Inspect the valve stem and handle adapter for damage
Install the new handle adapter, if required
Align the new handle with the valve stem
Slide the new handle into place
Tighten the set screw or mounting screw
Reinstall the escutcheon plate, if removed
Turn the water supply back on
Test the handle for proper operation and leaks