Use a water hose to rinse the sidewalk clear of the moss. The pressure from the hose will push most of the moss off the sidewalk. Remove any remaining moss with a brush broom.
Wear a pair of rubber gloves to prevent skin irritation caused by cleaning chemicals.
Fill a bucket with 1 gallon of water. Add 1/2 cup of bleach. Alternatively, substitute the bleach with trisodium phosphate (TSP).
Scrub the sidewalk with a scrub brush saturated in the mixture. Or you can use a brush broom saturated in the mixture, so you do not have to bend down while scrubbing.
Continue scrubbing the sidewalk in a vigorous motion and saturating the brush until you have removed all traces of the moss and thoroughly cleaned the sidewalk.
Rinse the sidewalk clean with the water hose. Begin at one end of the sidewalk and move the water hose in a steady back-and-forth motion that slowly moves upward.
Allow the sidewalk to air dry. Sweep your sidewalk regularly with a broom to keep it clean and clear of debris.