Clear the surface of debris and stains. Sweep it with a stiff broom and scrub it with a brush and concrete stain remover. Rinse off all solutions with a hose and wait about a day for the surface to dry.
Inspect the concrete for any cracks or pits. Fill the damaged area with vinyl concrete patching compound using a putty knife. Re-stamp the patched concrete if necessary by laying a textured rubber stamp over the patch.
Roll clear penetrating sealant over the stamped surface with a roller brush. Apply a thin coat and roll off any drips. Once the first coat dries, apply a second thin coat to guard it from foot traffic and water damage. Use the same sealant used previously, or one that is compatible. Choose clear sealant unless you want to alter to existing color of the concrete.