I _just_ replaced with double platinums and I also did the wires. The truck runs superbly with the new plugs, but that *might* be because the stock motorcraft plugs hadn't been changed in eons.
I also replaced the wires, and since the motorcraft wires suck (become one with the plug, broke into 5 pieces upon removal) I'd replace them as well.
Someone just posted about busting up their hand on spark plugs 2 & 3, but I took advice of other members here and went in through the wheel well. Just watch out for the toilet float "" that is mounted to the inside front of the passenger wheel well liner. It came out, but it didn't want to come back in--also, there are a few wires and tubes attached to the liner, but they come out problem free.
I got some frustration out of it, but going in through the wheel well left me injury free. Since I don't believe you can actually _see_ the spark plugs looking down from the hood, it'd be touch 'n go to get them in and out, and that failed in my experience with it.
Good Luck.