Clean the existing worktop with a degreaser and steel wool pad. Wipe down and rinse with a rag and warm water.
Rough the worktop's surface with medium-grit sandpaper. Wipe up any dust with a tack cloth thoroughly once the surfaced is roughed.
Lay laminate sheets over the worktop and trace the edges of the existing worktop with a pencil. This will give you a visual line to follow to cut the new laminate sheets to fit your worktop.
Place the laminate sheets on a workbench or table. Score along the traced lines with a utility knife on one side, then flip the laminate sheet over and score the opposite side. Snap the excess off along the scored lines.
Set the cut laminate sheets back in the kitchen, standing them on their sides on the floor. Apply contact cement to the old worktop with a paintbrush.
Lay wood dowels across the old worktop about 1 foot apart while the contact cement is still wet. Set the cut laminate sheets over the counter, on top of the wood dowels. Line up the edges of the counter and laminate sheets, then pull the wood dowels out slowly.
Press and smooth the laminate sheet onto the old worktop with a laminate roller. Let the contact cement dry for 15 to 30 minutes, or the time suggested by the manufacturer.
File the edges of the new laminate with a metal file to smooth and make flush with the edges of the counter top. Clean with a sponge using a mixture of warm water and white vinegar.