Measure Countertop
Measure the countertop's length and width and select the laminate material for your new pre-fabricated countertop.

Shut off Water Valves
Shut off the hot- and cold-water valves under the sink to turn off the water supply to the tap above.

Confirm that Water Supply is off
Turn on each faucet to confirm that the water supply is off.

Place Tray Under Piping
Put a tray under the piping beneath the sink to catch any residual water trapped in the water lines and drain as you disconnect them.

Disconnect Water Lines
Disconnect the water lines, using open-end wrenches, letting any water run into the tray.

Remove P-trap
Take the P-trap off the drain and dump the water out of it into the tray.

Remove Screws and Blocks
Remove the screws and blocks that hold the countertop in place. Facilitate locating the screws by removing drawers and opening cabinet doors prior to looking on the underside of the countertop and base.

Try to Lift Countertop
Try to lift the countertop. Caulking along the edge of the backsplash where it meets the wall may be holding it.

Cut Along Caulking
Use a utility knife to cut carefully along the caulking at the edge of the backsplash without damaging the wallpaper or other decorative surface.

Loosen Countertop
Slide a wide putty knife between the wall and the backsplash to protect the wall from damage while you lever against it with a pry bar to loosen the countertop.

Remove Countertop
Remove the countertop and carry it outside for disposal.

Confirm that Sink Cutout is Right Size
Bring in the new pre-fabricated countertop. In our project, the countertop came with the area for the sink partially cut out - that is not usual, so we will need to confirm that the cutout is the right size and shape for our new sink model.

Cut Cardboard Sink Template
Cut the cardboard sink template from its packing box and place it over the cutout on the countertop. In our project, the cutout and sink fit well.

Attach Temporary Clamps
Attach some temporary clamps to opposing corners of the cutout to hold it up while you finish sawing it out. Make the clamps by screwing some scrap lath strips into the top and bottom of the cutout - not into the countertop. These should overlap onto the countertop like a finger and thumb grasping the cutout.

Finish Sawing out Cutout
Use a jigsaw to finish sawing out the cutout.

Remove Clamps
Unscrew and remove the temporary clamps while someone grasps the cutout and discards it. (With very little work, a do-it-yourselfer can reshape and recycle the laminated cutout into a nice work surface of some kind.)

Set Countertop in Place
Set the countertop in place and secure it to the cabinet base with wood screws.

Apply Plumber's Putty
Apply plumber's putty to the perimeters of both drain cutouts, working from the upper side of the sink.

Insert Sink Baskets
Insert both sink baskets and tighten them against the putty to make waterproof seals. Trim away any excess putty.

Apply More Plumber's Putty
Apply more plumber's putty to the tap and faucet fixture and tighten them against the countertop to seal them again water. Clean off the excess.

Re-attach Drainpipe and Waterlines
Re-attach the drainpipe and waterlines by applying pipe thread compound to the connecting threads and then tightening the compression nuts.

Apply Silicon Sealant
Apply a bead of silicon sealant around the sink's lip to ensure a watertight bond where it will rest on the countertop.

Position and Gently Drop Sink into Place
Position the sink over the cutout in the countertop and drop it gently into place. Clean off any silicon sealant that may ooze around the edges to make a neat seal.

Secure Clips
Secure the clips at the corners of the sink to attach it to the countertop.

Make Final Connections
Make the final connections for the drain and re-attach the waterlines beneath the sink. Finally, turn the valves on to re-start the water supply.