Changing your spark plugs is not a fun job, but can be done with some patience. The 5.4 has coil on plugs on each cylinder. The first thing to do is remove the coils one at a time by removing the 7mm hold down bolt and inserting a 5/8 socket with an extension to remove the plug. The passenger side isnt to bad till you get to the back 2. I always use a couple short extensions to get in this tight spot. The drivers side is easier if you remove the two 8mm bolts that hold the fuel rail on the injectors and gently pry the rail up. This allows you access to the rear 2 plugs as the fuel pressure regulator can get in your way. Once you have the plugs changed reinstall the fuel rail on the injectors making sure that all injectors are started. An easy trick to install the new plugs is to take a 8in piece of 3/8 fuel line and stick the plug in it and use this to start the plug in the hole. If it were me I would replace the spark plug boots as well.