When hair, soap and other debris clog your bathtub waste line, water drains slowly; this can actually be dangerous, because it creates a slipping hazard. It often takes a snake to clean a clogged bathtub drain, but to get the snake into the drain, you have to remove the drain stopper. There are at least five different types of stoppers; some are stand-alone and some function in conjunction with a lever on the side of the tub. You can usually unscrew stand-alone stoppers, but removing a lever-style one may may require removal of the lever.
Open the stopper. If your tub has a trip lever, you can often simply lift the stopper out of the drain. It may be connected to a rocker arm. If so, lift the stopper about an inch above the drain, and then move it horizontally toward the center of the tub to pull the rocker arm out of the drain. You may have to wiggle it to get the rocker arm to clear the drain.
Unscrew the stopper by turning it counterclockwise, if it's a toe-touch type. This type of stopper stays down when you push it once and opens when you push it a second time. If you can't unscrew it by hand, wrap a towel around it; then grip it with adjustable pliers, and turn it with the pliers.
Remove the knob from a push-pull stopper, which works the same way as a toe-touch one, except that it's designed to operate with your fingers. The knob screws off; if you can't unscrew it by hand, wrap a towel around it, and unscrew it with adjustable pliers. Once it's off, unscrew the post to which it was attached using a screwdriver. Lift out the post, and then remove the stopper.
Use the same procedure to remove a lift-and-turn stopper as you would use for a push-pull stopper. A lift-and-turn stopper stays down when you push and twist it. Its parts are virtually identical to those of a push-pull stopper.
Open the toggle of a flip-it stopper, which uses O-rings to seal the drain when the toggle is closed. Wiggle the stopper back and forth to loosen the O-rings, and then lift it out of the drain.
Remove the lever cover plate if your tub has a plunger-style stopper. The actual stopper is located behind the tub wall, and the drain usually has a strainer. After unscrewing the cover plate, lift the plate and handle straight up; the plunger linkage will come with it. Once the plunger is removed, unscrew the strainer from the drain with a screwdriver to access the drain.