Remove the overflow plate, which is a metal plate under the tub faucet. Put on your work gloves, which should be made of rubber. Remove any hair that has become entangled. Check if the drain is still blocked by running the faucet for a few seconds. Replace the stopper device and overflow plate if the drain already flows freely. If the drain is still clogged, use a plumbing snake to clear it out. Insert the snake's tip into the opening. Keep turning the handle and pushing the snake forward and down into the pipe. Crank and push until the snake interacts with the block. Turn the handle and rotate the cable until the snake pushes its way through the blockage. To get the snake out of the drain, gently crank the handle backward. This will be dirtied, so clean it off with paper towels and throw them away as you go. Screw the plate back on after replacing the stopper mechanism and overflow plate.