Use a screwdriver to remove screws from the old benchtop. Use a putty knife, utility knife, hammer and pry bar to remove the old benchtop from the cabinet.
Lay a piece of 3/4-inch medium density fiberboard (MDF) on a stable work surface. Place the old benchtop on the MDF and trace its outline onto the MDF using a pencil.
Place scrap pieces of 2-by-4 boards on your work surface and lay the MDF sheet on them. Use a circular saw to cut the MDF sheet along the lines you drew. Use a jig saw to cut the details.
Draw the outline of the benchtop on the laminate, leaving a 1-inch allowance on all sides. Use a carbide-tipped cutter to cut the laminate. Also cut strips of laminate the same width as the MDF sheet thickness for the edges.
Use a brush to apply contact adhesive to both the back of the laminate and the MDF sheet's top surface and side edges. Press the laminate into the MDF sheet using a J-roller
Hold a laminate trimmer against the laminate and move it from side to side to remove excess laminate material.
Lay the benchtop on the kitchen cabinet and drive screws through the top of the bottom cabinet into the bottom of the benchtop to keep it in place.