Put on rubber gloves, protective goggles, a respirator and old clothing that can be discarded or immediately laundered. This will protect you from airborne mold particles, which can be harmful if inhaled.
Dampen the moldy area to reduce the number of airborne mold particles. Saturate the mold by spraying it with plain water in a plastic spray bottle.
Scrub the area on the wood where the mold is. Use a wet, stiff-bristled brush and scrub in small circles to remove as much mold as possible.
Remove any mold spores left after scrubbing with a stiff-bristled brush by sanding with medium-grade sandpaper. Sand in the direction of the wood grain until the discoloration from the mold spores is no longer evident.
Disinfect the bare wood with a solution of 1 1/2 cups of bleach to 1 gallon of water. Apply the solution by spraying it on with a plastic spray bottle or wiping it on with a clean cloth saturated with the solution.
Allow the disinfectant solution to air-dry on the bare wood; do not wipe it off with a cloth or towel.