Turn off the water supply if needed
Place a bucket under the sink
Remove the old plug from the drain
Unscrew or detach the lift rod or linkage if present
Remove the stopper assembly from the drain opening
Clean the drain area and remove debris
Check the size and type of the replacement plug
Insert the new plug into the drain opening
Reconnect any linkage or lift rod
Tighten all fittings securely
Test the plug by filling the sink with water
Adjust the fit if the plug does not seal properly