How to Replace a Bathroom Countertop
Remove the sink. Begin by turning both water valves clockwise. That will shut off the water supply to the sink. You can disconnect the water lines at this time. Using a crescent wrench, turn the nut just above the shutoff valve counter-clockwise until the line comes off. Repeat this process for the remaining water line. Disconnect the drain pipe by turning the sink drain nut counter-clockwise until the drain comes apart. Look under the sink and you will find the clips that hold the sink in place. Take a screwdriver and remove all of the clips by turning the screws counter-clockwise until they come off. You can now lift the sink out of the countertop.
Remove the countertop. The countertop will be attached to a cabinet or base. Start by looking under the countertop for the screws that hold it in place. Those screws are generally found in the upper corners in the cabinet. Remove the screws. You can now lift the countertop off its base.
Fit the new countertop and cut a hole for your sink. Place the countertop in place to be sure it fits properly. Once that's done, remove the countertop because you will need to cut a hole in it for your sink. Start by laying the sink upside down on the countertop. Make sure the sink is centered, and then trace the sink with a pencil. Remove the sink. Draw a line inside the traced line parallel to it and 3/4 of an inch from it. Doing this will leave a lip for the sink to sit on. Drill a hole on the inside line that is big enough to fit a jigsaw blade in. Place the jigsaw blade in the hole and cut along the inside line. The countertop is now ready for the new sink.
Install the countertop and sink. Place the countertop back in its place and insert the screws in the previous holes. Tighten the screws. Place the sink it its hole and replace the clips that hold it in place on the bottom of the countertop. You can reattach the drain at this time by putting it back in the hole and turning clockwise until it is tight. Reattach the water lines by screwing each nut back in its place, turning them clockwise until they are tight. Turn on the water supply by turning the two water valves counter-clockwise until they are fully open. Your sink should now be functional.
Caulk the edges of the countertop. Using your bathroom caulk, squeeze the tube and move the tube along each seam evenly to leave a uniform bead of caulk. Doing this will prevent the water from damaging the interior wood of the countertop and prevent any leakage from going under the countertop. Congratulations on a job well done.