This was kind of a pain in the butt. If I wasn't already totally certain my wires were shot, I don't think I'd do it again, even if there was a shred of truth to vendor HP gain claims. I took a few pictures along the way and recently completed the process, thought I'd share. I didn't look in the manual throughout this process, so this way isn't necessary the best, or even the right, way to do this. If you try to do this and blow up your hemisphere, don't blame me. My car is a 2004, so this should work for the '03-'06 cars.
Step 1: Open the hood (don't worry, it gets harder)
Step 2: Remove airbox. This is pretty straightforward, two plastic screwy things in front and a flat-head-screw clamp in rear.
Step 3: Remove connectors to throttle body. The throttle cable comes out when you pinch the plastic thing back through the black bracket, and un-clip the cable end. There are four or so electical connectors, some are simple pinch-and-pull, others have a sort of plastic safety lock to them. There are two cables on brackets under the throttle body, I found it easiest to just unbolt the brackets. There's some kind of PCV pipe there too. If you have trouble getting through this step, you may not wish to continue...
Step 4: Unbolt intake manifold. It gets a little tricky here. IIRC, there are basically 2 bolts per cylinder, 10 per side for a total of 20. Everything uses the same fasteners - 11mm bolts, and are keyed on top for a T30 Torx bit. The closest ones are easy to get with your favorite wrench. The rearmost one on the driver side I found not too bad once I moved the plug wires out of the way and went at it with a short (~5") wrench. The rearmost one on the passenger side I used a socket with a universal, not too bad either. The front-most one on the driver side, I found easier once I had unbolted the fuel rails and lifted them out of the way. This moves the between-rails fuel line out of the way of that bolt.
Speaking of fuel rails, you probably want to relieve fuel pressure here. Not sure what the manual says. I unclipped the injector electrical plugs by "spreading" the plastic sides and pulling them back. With only 11k miles mine felt pretty brittle already so be careful. I chose to leave the injectors in place in the fuel rail, which didn't cause any fuel leakage problems, but if you pull an injector out of the rail without relieving pressure, you'll have a mess. Three of the same-spec bolts per side hold in the rails. Once unbolted, pry slowly can carefully to lift the mess out. Be gentle with the injectors too once they're out, they're fragile.
Oh, should probably mention you can/should disconnect the battery if you're worried about shorting stuff out. I didn't but then again I may have eaten too much paste in school.
Anyway, there are about 3 per side (the "inner middle 3") you can't get an open-ended wrench around, and there isn't enough room from the sides for an open-ended wrench or ratchet. For those, use a socket on a couple extensions, and feed that whole mess through the openings between the runners. Ends up being pretty easy if you do it that way, with one exception-
The second-rearmost bolt on the driver side is a really crappy mess. The usual attack-from-above trick doesn't work because of the angle of the runner. Trying to do anything from the side is made way tougher by the brake booster port. My 3/8" ratchet hardware wouldn't fit through the smaller hole in the intake here. Had to dig through my Fisher Price tools (joke) to find some 1/4" drive stuff. As you can see above, I couldn't really get my small 11mm socket to fit on the bolt. I don't have a universal for my 1/4" drive stuff, but I'm not sure it would have helped. There is probably some kind of fancy open-ended crow's foot wrench, of super-low-profile ratchet hardware that would make this part easier, but nothing in my pretty standard toolset would do it. I ended up getting it out (and back in later) with my Torx bit, but the whole thing was a little dodgy.
Step 5: Remove intake. In addition to what's been done already, there is the brake booster connection and a PCV connection on the driver and passenger sides to remove. Also, the injector wiring harness has 2 yellow-ish push-in clips per side holding it to the manifold, remove those now. Try to tuck the injector wires back underneath so they don't get caught removing the manifold.
Once that's done, the whole beast should lift out-
The tortoise lays on its back, its belly baking in the hot sun, beating its legs trying to turn itself over but it can't. Not without your help. But you're not helping.
And hey, at last, the other end of our spark plug wires!
Step 6: Old wire removal/new wire install. Old ones should come out pretty easily. I ordered new wire holders with my wires (the AB wires BTW) so I elected to replace them all. My particular car had a pretty rough previous life, having had headers, and the hastily/sloppily been reverted to stock manifolds and heat shields. The accessible wire holders were all cracked to pieces, or missing entirely. It's just as well, their diameter would have had a hard time holding the AB wires. As it was, I had a pretty hard time getting the AB wires to fit into the new wire holding clip things. Maybe I'm just a pussy?
Take your time to run the wires the way you want so they look how you want. I suck at aesthetics but it still took me a while to keep 'em from being too tangled. As you put them in the holders, be sure to leave some slack so they don't get tugged when you close the holder thing up.
Old clips on right, new on left-
Here's how I knew I needed new plug wires, this plug boot, as well as a couple others, had been resting against a sharp edge of the heat shield and got all cut and toasted.
Here's the passenger side pretty much put together. I re-used the black plastic shielding stuff from the stock wires on the AB wires, which is probably overkill, but whatever. I don't want to ever have to do this again, unless maybe I'm throwing on some race heads or something next time.
Installation is pretty much the reverse or removal. I took this opportunity to clean some things up like the manifold and throttle body, and vacuum up all the crap that'd fallen in the V engine's valley. That one bolt on the driver side becomes a problem again, I had a hard time convincing it to start threading in because of the angles. You'll have to be patient, or get the magic tool I don't have, whatever it is.
As a bit of advice, when bolting together things like this where there's 2 big flat planes coming together to form a seal, it is usually good to try to jump around a bit from bolt-to-bolt as you tighten, and do it in a few stages. Sort of like when bolting down a cylinder head, it helps ensure things come together squarely and form a good seal.
All done! Enjoy a beer and try not to ever do again whatever it is that necessitated this wire change-out.