Break the caulk seal around the edges of the laminate countertop with a utility knife.
Unscrew the laminate countertop from the cabinets with a screwdriver. Underneath the countertop there should be small blocks glued to the cabinets. The laminate countertops should be screwed to these blocks. Unscrew the countertop.
Lift the laminate countertop from the cabinets with the help of a partner. Work carefully so you do not damage the countertop. The countertop will be used as a template to cut the butcher block to size.
Cut or order the butcher block to size. You may be able to purchase the butcher block already cut to size. If not, use the laminate countertops as a template for the new countertops. Mark the countertop with a pencil and then cut it to size on a table saw. Sand the cut edges smooth with fine grit sandpaper.
Apply a bead of kitchen and bath caulk along the top edges of the cabinet. Set the butcher block in place on the caulked cabinets.
Locate the mounting blocks inside the top of the cabinets. Place a deck screw -- shorter than the thickness of the countertop -- through a fender washer. Screw the deck screw into the mounting block so the butcher block is tight against the cabinet. Repeat with all of the mounting blocks.
Apply mineral oil to the butcher block with a lint-free cloth. Let the oil soak in for five to 10 minutes and then wipe away any extra. Oil the butcher block countertop monthly.