headlight aiming and removal help

I have a 1998 z71 silverado; the left headlight is aimed way too high so I attempted to adjust it through the top of the radiator mount with the torx head driver. i could not get the headlight to adjust down, so i then attempted to remove the light assembly as described in the manual, however the post that holds the assmbly in place from the middle of the assmbly will not backout of the mount hole, it will turn but it will not release and slide up and out . the other mounting screw will back out and i was able to remove it.
anyone have any ideas? or had this problem w/ solution?

Thanks
Derek

ok. I found the problem... the mount behind the light was broken and the nut was spinning as i tried to back out the screw.

now i have a question about. the aiming. the aiming screws when turned dont appear to adjust in or out ,, do these aiming screw mechanisims stop working after a while????