It's not very difficult at all. You will need a deep socket set of sizes 10mm through 13mm with an extension, and a 5/16 socket, plus probably a couple basic hand tools like screwdrivers and such.
You'll need to remove the upper intake manifold. This is just 6 nuts, though you'll probably need to unhook a few minor things to set the manifold aside. Tag them and take pictures so you know where to put it all back. If you have EGR, that will be hanging onto your manifold but you can either use a large adjustable wrench or unbolt the EGR valve from the manifold. Same for DPFE sensor, if equipped. Basically you need to get the upper intake manifold out of the way so you can get at the fuel rail. Once there, first depressurize the rail by removing the cap from the test port and poking the shrader valve pin to release pressure (like a tire valve). Then you can remove the fuel supply line from the regulator with an adjustable or box end wrench. Pull the vacuum reference line off the regulator, then the two bolts (5/16 head) that attach the regulator to the fuel rail. The regulator will then pull out and you can swap the new one in.
Re-assembly is the reverse of removal. I do recommend replacement of any gaskets you come across, if it is in your budget.
