Grasp the front edge of the enameled worktop. Pull the worktop straight out from the front of the cabinet until it stops.
Lift up on the front edge of the cabinet so that its built-in stops clear the stops built into the top of the base of the cabinet. Pull the top outward, then lift it straight up and remove it from the cabinet.
Turn the worktop upside down. Remove the retaining screws that fasten the worktop to the wood framework from the edge of the top with a flat blade or Phillips screwdriver, depending on what fastener is used on your cabinet. Lift the framework from the underside of the top and remove it.
Position the replacement enameled worktop upside down on a blanket or pad to protect the finish.
Lower the wood framework onto the underside of the worktop. Replace the screws through the small holes in the sides of the top and tighten with a screwdriver.
Lift the worktop assembly and position it over the cabinet. Push the top horizontally towards the back of the cabinet until the stops in the top ride over the stops on the cabinet to lock it into place.