if its just little spots, most bleach-based cleaners will be sufficient to kill the spores. Spray it directly on, let it soak for a few minutes (you should see the mold dying and fading), then wipe it clean with paper towel and dispose in trash. Preferably wear a face mask and gloves, and ventilate the area that you are using the bleach in.

if the mold is taking up meters of your wall, or its a porous surface like wood, then you probably need professional cleaning/replacement.