6mm* Allen key here screws the FRONT of the light down or up: Turn LEFT for up, right for down. I have to think of them like sprinkler faucets: Turn left to make them go higher.
* Unlike most 6mm nuts/bolts, a 1/4" tool won't fit. My sharpest newest 7/16 barely works though, or a slightly-under-quarter-inch screwdriver blade, since it's low-torque:
* Unlike most 6mm nuts/bolts, a 1/4" tool won't fit. My sharpest newest 7/16 barely works though, or a slightly-under-quarter-inch screwdriver blade, since it's low-torque: