A bathtub has two separate drains. The first drain is at the bottom of the bathtub. The second is the overflow tube drain. It is located underneath the faucet. When the water in the tub rises over the overflow-tube cover plate, the water drains down the overflow tube, preventing flooding. It may be necessary to remove the cover plate on occasion to clean out the tube, especially after an overflow.
Press a rag into the drain at the bottom of your tub. This prevents screws from falling down the drain.
Remove the two screws holding the cover plate in place using the screwdriver.
Pull the cover plate off the overflow hole.