Turn off the shower water
Remove the old shower head by turning it counterclockwise
Clean the shower arm threads
Wrap plumber’s tape around the shower arm threads
Screw the new shower head onto the shower arm by turning it clockwise
Tighten it by hand
Use a wrench gently if needed, with a cloth to protect the finish
Turn the water back on
Check for leaks
Tighten slightly if leaks appear