Two things:
One, a tip. If you haven't tried it, try moving the wheels full left or full right. On my '99 F150, full left pulls the pitman arm out of the way and makes it MUCH easier to get at it.
Two, I am surprised Ford did not install the handy dandy oil funnel on yours. Mine has a nice black plastic piece under the oil filter location that routes the oil that drips out over the differential nice and clean. No problems there. Surprised it isn't on a later model!