Mold is a new one on me - I have seen moss, lichen, and tree sap cover or discolor pavers, but never mold - these pavers must never see the light of day.
A 50% chlorine bleach solution in warm water swabbed over it and let sit for a couple of minutes, then scrubbed with a hard bristle push broom or scrub brush would work, but might discolor and bleach the color, if that bothers you.
A tub and tile mold remover will certainly work, but also might discolor it or leach the color.
I woud use one of the above, but if you are real concerned about discoloration or some bleaching, then I would use a very stiff nylon scrub brush (available at building supply stores) and alcohol, or sandblast it clean, if you have a sandblaster.
A pressure washer will also work, but you will have to be very careful not to groove or leave a swirl pattern in it while still using enough pressure to clean it off, especially with colored or stained pavers. Follow up with a Borax (NOT Boraxo soap - pure Borax, in laundry dry soap section of your store) to reduce regrowth.