I just installed my UPR off-road x-pipe and have a few notes/observations for anyone who will be tackling this soon. Much of this may be covered in instructions that may come with other brands, but I had no instructions and some of this was a bit tricky to figure out. I also did the entire install on jackstands and would highly recommend anyone planning to do this themselves gain access to a lift.
There are two nuts that must be removed on each side that secure the stock cats/h-pipe to the stock headers. We were able to break all these free using hand-tools but penetrating lubricant was needed. We used ZEP, but anything should get the job done. Don't bother trying to break them free without doing so first. The driver's side was very easy to break loose, all that was needed was a 15mm socket and a slightly beefy 3/8" ratchet. The passenger side had one bolt that was relatively easy, but the one on the top/closest to the engine was a bit more difficult. We removed the plastic cover from the wheel well to get some better visibility, but you could do this without removing it. We were only able to get to this using two extensions and a swivel and it was a total bitch to transmit enough torque through all those joints.
The factory h-pipe is connected to the stock over-axle pipes using two slip joints that are secured with four bolts. These were very easy to break loose using a 1/2" ratchet and 15mm socket without any lubricant. I also recommend having a small flat-head screwdriver available. There is a catch on the slip joint that needs to be lifted to clear a stud on the stock h-pipe for removal when sliding off. Before removal, be sure to disconnect the rear O2 sensors using a 15mm wrench (I just let these hang free during the rest of the install).
I tried attaching the new x-pipe in a variety of ways, but the only way that worked for me was to loosely assemble the entire thing and thread the nuts/bolts at the headers just enough to hold everything in place before connecting the slip joints from the over-axle pipes. Once I had everything loosely fit I started working from front-to rear tightening everything up and didn't run into any problems.
-my specific brand of x-pipe did not come with nuts/bolts or gaskets
-the bolts will need to be less than 1/2" in diameter and about 1-1/2" long
-no parts stores seem to carry the gaskets that fit between the headers and x/h-pipe, if you plan on replacing these you should allow time to get them from Ford
And here's the video ... there's a bit of smoke from the cold and the sta-bil in the fuel system that's been sitting for a bit.