on 67 and 68 ones there are a set of screws that you turn to adjust the height of the doors. on 69 and 70 to be honest, i dont know. what year is it for???? ill look around and see if i cna find any site that has pics of it. not hard to do, but kinda hard to explain ( well for me anyway ) without visual aids.
Sorry forgot to let you know the year 67.
Also just went to a show 1 cougar (mine). Cruse night got stuck between 2 mustangs. People looking had to remind them that it is a cougar not a mustang. My 67 is far from show but new paint and a good body makes her look nice.
And back to the head light doors?
ok, here is a pic of the headlight assy. Just imagine it is still on the car. The bolt with the rubber bumpstop will adjust the door position when the door is open. I am not sure about alignment when it is closed. Maybe the springs or vac. motor need to be replaced. I would check for you, but my light assy's are all disassembled waiting for powdercoating.
If you look to the side of the above mentioned adjuster for the open position(can't remember which side though), you will find the adjuster for the closed position. It's rubber pad is hidden under the bracket...all you see is the end of the adjusting bolt.
PS. If you look at Crazycat's picture, the end of the adjusting bolt is just below the arrow head!