To get started, remove the old sink. (Note: Don't forget to shut off the water)If you have an old wall hung sink, disconnect the trap and the supply lines. Cut away the caulk sealing the sink to the wall. With some models, you simply can lift them up and away. Others are connected to mounting brackets with bolts, which may be rusted. Use penetrating oil or cut through them with a hacksaw.

Next you need to install the plumbing in the cabinet. Install new stop valves and a drain line, making sure they will be covered by the vanity cabinet and won't interfere with the sink.

If the cabinet has a back, measure and cut holes for the pipes. Slide the cabinet into position and level it in both directions, using shims if necessary. Anchor it to the wall with screws into the wall stud.

Install the faucet, flexible supply lines, and drain assembly on the sink. Set the sink on top of the cabinet. Make sure it is centered with the backsplash tight against the wall. Attach the sink to the vanity. Connect the drain trap and the supply lines. Run a bead of caulk where the backsplash meets the wall.

Lastly you need to connect the pop-up assembly. Insert the ball rod into the opening and secure it with the nut. Slip the rod through the clevis strap and secure it with the string clip. Lower the pop-up rod down through the whole in the faucet spout. Slide on the clevis strap and tighten slightly. Adjust the clevis so the stopper seals when the rod is pulled up. Tighten the screw and you're done. An easy upgrade that just added value to your bathroom.