Remove the doors of the cabinets from their positions on the wall by unscrewing them from their hinges. Remove all hardware, knobs and locking mechanisms, setting them aside for later. Remove any other panels to be resurfaced. Clean the panels thoroughly with soap and water. Allow the panels to dry.
Sand all surfaces of the removed panels using medium grit sandpaper and sanding with the grain of the wood. Wipe off all sawdust that has accumulated on the panels.
Brush a coat of paint or stain over the surfaces of the panels that will show. Apply thin, even coats using smooth and steady brush strokes that match the direction of the sanding. Allow the first coat to dry for four hours. Apply a second coat in the same manner and allow it to dry for four hours. Repeat as needed until the stain or paint has completely covered the old color of the panels.
Apply a light, even coat of polyurethane to the painted or stained surface using very smooth strokes of a clean brush. Apply the polyurethane in the same direction as the paint or stain. Allow to dry for four hours and apply a second coat. Repeat the process for four coats of polyurethane or more coats if the cabinets are going in high traffic areas, such as large family kitchens. Allow the panels to dry overnight.
Reinstall the panels to the wall cabinets using the hardware that was previously removed.