in my experience, there are two significant challenges to this job. for a high mileage engine whose intake has never been removed. first, removing the torx bolts (8) -- especially the rear ones, under the cowl -- is tricky. be sure to vacuum/blow off with compressed air the heads to get all the crud out of the torx well first. torx bolts thankfully are harder to strip, but I managed to do so on one of these once (thank goodness on a front one, where I could drill off the head and removed rest with vices grips after I got the intake off). get yourself a good, swivel head 1/4 inch ratchet and a good selection of short extensions, including wobbles. take the hood off completely or tie all the way back.
the other challenge are the valve cover bolts, many of which had corroded on my 179k miles 4.0 SOHC. lots of PB Blaster and hammering on a 7 mm deep well socket when the stock 8 mm ones rounded off.
replace both valve cover gaskets when you have the intake off. note that you may need to replace some valve cover bolts, so be sure to have a way to get to the local ford dealership while open for those. same with some of the intake bolts (dealer only item). I replaced the rear ones on mine.
I generally like Felpro gaskets, but one of them is leaking already, so I'm planning to replace it with mahle/victor reinz on that side soon. I'm glad I replaced the worst bolts, and used anti-seize on the intake bolts when I re-assembled mine.