BLkSc300

i have done a search on adjusting the headlight... but i was wondering when i turn the the black bolt, is the plastic **** suppose to turn with it too?...It weird becuz i thought the black bolt controls the vertical alignment, but i also have another problem that no matter how much i turn it the light won't go up or down.. But i found out that if i pull the plastic **** out the know won't follow the black bolt when i turn it. but by trying it numberous times the bubble in the beam angle gauge still won't budge. did i miss something here? please tell me if i did.. thanks in advance