Prep and Cut the Countertop
Dry fit the vanity top. In our project, we installed a granite countertop and backsplash from a company specializing in remnants.
If the granite hasn't been pre-cut to accommodate hardware specifications for your vessel sink drain and faucet, measure and cut any required holes in the granite. Use a marker to trace the sink's drain hole onto the countertop, marking the center of the circle (Image 1).
Use a nailset to chip a small amount of material from the granite countertop. This will keep the drill bit from sliding and scratching the granite.
Attach a diamond-tipped hole saw bit to a heavy-duty, corded drill. Cut a piece of sponge approximately the size of the hole saw bit and place it inside the hole saw.
Dip the hole saw in water, then carefully drill a hole at the position marked (Image 2)
Dip the hole saw and sponge in water periodically. This will keep the saw cool and will help lubricate the cut. Remember to keep the saw straight up and down so the hole doesn't tilt to one side. If muscle fatigue makes it hard to control the saw, be sure to take a break and recover.
Repeat the process for the faucet supply lines, as appropriate.