Remove the drain cover/strainer screws (if present) with the correct screwdriver or wrench
Lift out the strainer/stopper assembly
If it’s a pop-up drain, remove the lift rod linkage from the overflow or stopper mechanism
Pull the stopper out (or unscrew it if it has a threaded connection)
If the drain has a threaded basket, use penetrating oil and loosen by turning the basket counterclockwise
If it’s stuck, apply penetrating oil and wait, then try again
Protect the tub surface with painter’s tape or a rag while using tools
Use a drain removal tool, adjustable pliers, or channel-lock pliers for grip on the drain basket (avoid scratching)
Remove any remaining flange or seal material from the tub opening
Unscrew and remove the overflow cover plate (if needed) and disconnect the linkage
For a glued/caulked drain, cut through caulk/sealant around the flange with a utility knife, then loosen and remove the drain
Clean the mating surfaces thoroughly
Replace the drain using a new gasket/putty as required, then reassemble and test for leaks