Sweep the walkway with a broom to remove debris such as pine needles, twigs and leaves.
Dig up as much moss as possible from the walkway with a flat-edged shovel. Use the tip of the shovel to get underneath the moss, then pull the handle toward you to dislodge it. Scrub the affected areas with a wire brush to further remove the moss. Sweep all the loosened moss off the walkway.
Mix equal parts water and chlorine bleach in a clean garden sprayer. Soak remaining moss spots with the mixture.
Let the bleach solution sit on the walkway for up to 20 minutes. Scrub the spots with a stiff scrub brush to loosen the moss.
Rinse off the walkway thoroughly with the garden hose.