To find it, you need to:
1. Identify your engine: Look for an engine code (e.g., 4.6L V8, 5.4L V8, 4.2L V6) on a sticker under the hood or in your owner's manual.
2. Consult a repair manual or online resources: Once you know the engine, search online (e.g., YouTube, a Ford forum) for "[Your Engine] oil filter location 1999 Ford [Truck Model]". Many videos and images will show the exact location.
General advice: The oil filter is usually located somewhere near the bottom of the engine, easily accessible from underneath the vehicle. It's often attached to the engine block itself. However, its precise location varies greatly between engine types.