Below are the directions for removing your headlight assembly in your 1997 F350. The lower retaining nuts are a little tough to get to. You may have to remove the battery and battery tray along with the air cleaner.
Remove two screws and two nuts retaining headlamp door (13064).
Pull headlamp door from vehicle. Remove three bulbs and sockets.
Disconnect engine control sensor wiring (12A581) from headlamp bulb (13007).
Remove two retainers attaching upper two attachments of headlamp (13008).
Turn horizontal headlamp adjusting screw (13032) completely out of the adjusting nut.
Pull headlamp from vehicle.
Follow removal procedure in reverse order.
Tighten screws to 1.4-2.3 Nm (13-20 lb-in). Tighten nuts to 4-7 Nm (36-61 lb-in).
Check headlamp aim. Refer to Headlamp in the Adjustments portion of this section.
Any other questions, please ask.