How to Remove and Install a Kitchen Sink Strainer
Step #2: Remove Sink Strainer Locknut
Use either a special locknut wrench or a large pipe wrench to unscrew the old sink strainer (turn counterclockwise).
To keep the sink strainer from turning, insert either a special basket strainer wrench (photo above) or needle nose pliers (photo to right) into the strainer opening.
Once the strainer locknut is loose, unscrew it by hand and remove the tailpiece and nylon washer.