Locate the sink stopper linkage under the sink
Find the horizontal pivot rod connected to the drain tailpiece
Loosen the retaining nut on the pivot rod
Pull the pivot rod out of the drain assembly
Lift the stopper straight up from the sink drain
Remove the stopper from the drain opening
Reinsert the stopper if needed by placing it back into the drain
Reconnect the pivot rod through the stopper hole
Tighten the retaining nut securely
Test the stopper movement up and down