A built-in sink plug provides a great convenience if you need to fill the sink with water. Rather than dealing with a removable plug, which can fall off the vanity and become lost, you simply need to pull up on the drain plug lever on the back of the sink to plug the sink and down to open the plug and let water pass through the drain. You can install the sink plug assembly in a few moments and without many extra items.
Open the cabinet under the sink, if there is one, so you can easily access the bottom of the bathroom sink. Use a flashlight if necessary to be able to see under the sink.
Slide the sink plug lever through the hole on the back side of the sink. Bolt the connector bracket onto the bottom end of the lever assembly under the sink so the end with the multiple holes it in hangs downward.
Apply silicone grease to the pop-up lever ball. Slide the lever ball end of the stopper rod into the opening in the back of the sink's drain assembly.
Slide the other end of the stopper rod through one of the holes in the connector bracket piece. Drop the sink plug assembly into the sink's drain.
Pull up on the sink plug lever to close the drain plug. If you see a gap, slide the stopper rod out of the hole in the bracket piece you put it in and slide it into a hole that sits higher in the bracket piece.