It's not terrible, really. I'm only 19 and figured it out on my own. Did it right in my garage with basic tools, plus an impact wrench. You're looking at 2-3 nights from start to finish. You take off your calipers and get your springs out first. Disconnect the steering shaft and hang the PS pump from the sway bar with some bungee cords or something. Support the motor (I put a jack under the crank pulley) and spin off the motor mount nuts. Then it should be ready to come down. There's two bolts on each side near the frame rails, and there's two nuts and bolts on each side up where the springs sit. Don't forget, that thing weighs like 90lbs so BE CAREFUL. I had two jacks and a buddy helping me. If you're letting it sit overnight without the K-member, don't leave your motor on a jack. Chances are it will slowly fall and cause all sorts of problems. I put jack stands under the motor mounts when I wasn't working on it.
As far as headers go, when removing the old manifolds, don't even try to take the front A.I.R. tubes off while they're on the motor. Unscrew them from the pumps and then wiggle the tubes out with the manifolds. Then, when your headers are bolted on, screw the tubes onto the headers, and then onto the pumps. The tubes weren't a perfect fit with the new headers, so unbolting the pumps from their brackets helped a TON in getting everything back together right.
I hope this helps, feel free to send me a message with any other specific questions. I highly reccomend Flowtech, they're made by Holley, only $299, and sure as hell woke this DOHC up!