Whatever you do! Don't become a headlight killer like me ;] I wish our headlights were simple to install/uninstall like the 99-04 mustangs ;[
BE CAREFUL WITH THE ADJUSTER.. THEY LOOK LIKE BULLETS LIKE TRUBBLE SAID. I BROKE ALL OF MINE ALMOST SO 1 LIGHT IS HANGING AND YOU CAN MOVE THE LIGHT FROM OUTSIDE. ACTUALLY, i adjust my lights daily to drive rofl by moving it up and down. There correctly adjusted, but on some roads its a pain to see because of the smoked lenses.
if its a 1997 mustang than i c an help ya straight through it.
1st of all. Your car doesnt have any tabs holding it in like 95KBGT's. Just forget that step b/c i litterally stood at my car for 10 minutes looking for tabs to pull. Thats only for the 5.0's i guess.
2nd. Theres a metal clip on the left top adjuster you need to pull it UP with pylers or something. Heres a pic of the clip (you will need to reinstall on your new headlights)-
3rd- All you have left is the 4 adjusters to squeeze the hell out of than your headlights will pull off.
4- With a pair of LONG needle nose pylers squeeze the adjuster where the sides budge out on them. Doing this should allow you to pull the headlight about an inch of so. Do this for all 3 of the adjusters and than pull on the whole headlight itself and it should pop out.
For the install.
1. When screwing/adjusting the adjusters make sure you screw the adjuster to were you can safely use the long needle nose pilers to remove it. I mean don't point the budging sides up and one down. You will end up breaking the adjuster trying to remove it if you need to readjust your lights (trust me.. its how i became a headlight murderer)
Warning. Those adjusters are pretty expensive once you break about 5. they cost 6.95 each. Buying a new set will cost $41 not including the shipping. If you do break acouple try your best to remove your old ones from your stockers. It took me hours to do mine and guess what.. i only got 1 off and the rest are rusted shut on the stocker headlights :'(
edit: you have a 1998 GT, so it should be similar to my install.