Remove the screws holding the drain’s cover in place, and then pry the cover off the drain’s opening. Place the screws and drain cover in a safe place away from the drain opening.
Insert the jaws of a pair of channel-lock pliers into the drain’s opening, and adjust the jaws so they press against the sides of the drain. Turn the drain body counterclockwise with the pliers, unthreading the drain body from the drainpipe below.
Remove the jaws of the channel-lock pliers from the drain if you cannot loosen the drain body, and then slide the pliers handles in the drain’s grid. Insert a long screwdriver between the pliers handles, and use the screwdriver to turn the pliers and drain counterclockwise.
Insert a drain key in the drain’s opening if the grids are broken or not present. Turn the dial on the drain key, expanding it against the drain’s walls until it fits snugly. Grab the top of the drain key with the pliers, and turn it counterclockwise to unthread the drain.