Insert a screwdriver into either of the two screws holding the clamp in place. Turn the screws counterclockwise until they drop free of the clamp. Repeat with the second screw.
Pull the clamp off of the pipe. A screwdriver may be required to gently pry the clamp off of the pipe.
Inspect the clamp for signs of corrosion or cracks. Remove minor rust by rubbing the steel with a fine-grit sandpaper. A severely corroded or cracked clamp should be replaced with a new one. If the clamp is in good condition, place it back over the pipe about an inch away from the holes of the previous screws. Place two new screws into the holes on the sides of the clamp and tighten them into the wood using a screwdriver.
Place a new clamp over the pipe if the old one is corroded or cracked. Screw the clamp into the wood about an inch away from the holes of the prior screws.