After continued use, a bathroom sink plug may become stuck, corroded or damaged and will have to be replaced. Sometimes the plug is not properly holding water in the sink anymore and is wasting water and will need to be changed out with a new part. It is possible to replace the sink plug or stopper yourself with a few basic materials.
Turn off the water supply to the sink by turning the shutoff valve under the sink.
Remove the old sink plug. Take off the old one with an adjustable spanner wrench and pliers. Loosen the nut that attaches the drain pipe under the sink to pull off the sink plug. Clean up any debris that have fallen out of the pipes with a damp cloth.
Cut out a long piece of plumber's putty with a utility knife. Place the piece around the edge of the sink strainer to create a tight seal.
Replace the connections that you took out from under the sink. Tighten any nuts and washers with pliers. Wipe off any excess putty from around the sink plug with a damp cloth.
Reconnect the tail piece pipe. Tighten it with a pair of pliers.
Replace the sink stopper by placing it into the sink's drain opening and testing that it works correctly.
Inspect the sink plug before you begin any work to see if it needs replacement. Sometimes it just needs minor adjustments.