Scrape off the old caulking around the spout using a putty knife.
Look for an Allen bolt found under or on the side of the spout. Use the appropriate tool, either a screwdriver or Allen wrench, to loosen the bolt.
Twist the tub spout in clockwise direction to loosen then pull to remove the old one.
Clean the area around the spout to prepare it for a new replacement. Use an abrasive kitchen scrubbing pad and some kitchen cleanser to remove any dirt or grime where the new spout will be mounted.
Now you are ready to attach the slip-fit spout into the connection pipe. Take the new spout and slip it into place.
Tighten the bolt using the appropriate tool to secure the new spout in place.
Apply new caulking around the spout to seal the opening between the wall and spout. Use your fingers to set the caulk neatly around it. Remove excess with a paper towel.
Allow the caulk to dry before turning on the water and using your bathtub again.