On my 1995 F250, it's as I thought I remembered: adjustable without dismantling. As an example: at the driver's side.... above the upper right corner of the lens is a small hex rod (3-4mm?) to make the up/down adjustment. Then behind the upper left corner of the lens is another hex rod (pointing towards the engine bay) to make the left/right adjustment. Had to remove the rubber trim strip to see that one. Will post pics later.