Its pretty easy to do yourself, I had mine done in 2 hours, but I took a bunch of extra time to really clean off the gasket surfaces before replacing everything.
The only tools you need are an in-lbs torque wrench, 1/2in sockets, 4in and or 8in extension, a flathead screwdriver, a gasket scraper (makes life easier), coolant and oil for a change, and a fuel line disconnect set (its possible to work around this, but for the price its worth it to just buy a set).
If you go with the hughes repair kit everything is listed out. But the just of it goes like this. Disconnect the alternator, unbolt the alternator and A/C compressor bracket and move it aside. Remove the air intake down to the throttle body, unplug all the electrical connectors from the throttle body. You can either unbolt the TB or just remove the cables attached to it (I found it easier to just remove the 3 cables and leave it bolted to the intake). Then unplug the electrical connectors from the injectors. To make your life easier, undo the harness clips that hold the electrical harness to the valve covers and move the harness out of the way. MAKE SURE YOU CLEAN ALL THE CRAP THAT IS SITTING BETWEEN THE HEADS AND THE INTAKE. Now you have 14 bolts around the perimeter of the intake, their locations are listed on the hughes diagram, once all of these are out, you may need that flat heat to gently pry up on the front of the intake t break it loose. After the intake is off, the plenum pan is on the bottom of it, it has 12 or 16 bolts I think. After you have it all apart scrape the old gaskets from the heads, intake and block. Install the plenum pan and gasket, install the intake gaskets and reverse the order of removal while following the torque instructions listed on the hughes kit.
After you have finished, change the oil unless you drained the coolant first, as a bunch of coolant has leaked into the engine.