Removing an overmount sink is a simple process that can be completed in just a few minutes. The first step is to turn off the water supply to the sink. Next, use a screwdriver or other tool to remove the screws that hold the sink in place. Once the screws are removed, you can simply lift the sink off of the countertop. If there is any caulking or sealant around the edges of the sink, you will need to remove this as well before installing a new sink.