The FSM has a good step-by-step on doing this - but in actual practice, there are other things that you should do to make your life easier during this procedure.
1. Unless you're accustomed to working in cramped spaces, and assuming you have power seats, remove the driver's seat.
2. Disconnect the negative battery cable at the passenger-side shock-tower post.
3. Remove wipers and cowl:
4. Remove strut tower brace:
5. Disconnect the brake-fluid level sensor from the master cylinder:
6. Get out your PB Blaster and hit the threads/bolts that hold the master cylinder to the brake booster (there are two). Let them soak for 15 mins or so.
7. Get (3) 12" socket extensions and your ratchet to remove the bolts. I used two extensions for the nut nearest the shock tower, and three to reach the other nut. Again, unless you have flex-adapters or something than can wiggle in behind the master cylinder to reach them.
8. There is a cable bracket that sits in front of the master cylinder mount, swing it up and out of the way. Pull master cylinder forward a bit, rotate it 180 degrees counter-clockwise and let it rest on the top of the engine (sorry - no foto!). Then you can see the brake booster in all its glory. Here's what mine looked like:
9. Disconnect the vacuum line from the booster:
10. Time to move inside the car. I *HIGHLY* recommend removing the knee bolster cover panel, and the steel knee bolster, as well as the air duct that runs across behind it (the lower one). Now you can see the 4 studs and the clip on the brake pedal that connects to the booster:
Here's a closer shot of the clip:
11. Use a small flathead screwdriver and remove the clip - if you use care, you MIGHT be able to reuse. I bought a new one ahead of time ($5?) from the local 5-star and I'm glad I did. I mangled the clip during removal.
12. Get out the deep-well 1/2" socket to remove the 4 nuts holding the booster to the firewall:
13. Now let's go back to the engine compartment - need to rotate the wiper motor mechanism to 12 o'clock position to make room to remove the booster. Turn the motor in a clockwise direction (you'll be going about 270 degrees) until it looks like this:
14. PRESTO! Booster slides right out! Ok, kidding about that. I had to disconnect two engine harnesses, remove the PCV hose, and generally do all kinds of wiggling to remove the doggone booster.
15. Close inspection of old unit - blech!
16. Okay - there's a foam gasket on the firewall-side of the booster - if it's not torn up too bad upon removal, install it onto the new booster:
I went a step further - since the old one was all compressed and some of it stuck to the old booster, I raided the wife's crafting supplies and made my own layer to put on top, for good measure:
It's a section of this stuff:
Here's the business end of the new unit:
Oh look! No corrosion!
17. PRESTO! It slides right in! No, of course not. It was slightly more difficult to wiggle into place, since you now have to align the 4 studs to the holes in the firewall.
18. Here's under the dash - bolted in, and the new clip affixed to the pedal.
A 'better' shot?
19. Re-attach the master cylinder to the brake booster - don't forget the cable bracket! Also reattach the vacuum hose.
20. One thing you should do, is reset the brake pedal switch. Grab the assembly, twist 30 degrees counter-clockwise, and it pulls straight out. Disconnect the harness and remove the switch from the car. Then firmly (I had to use pliers) but gently pull the plunger out (it will click/ratchet) to it's maximum extension. Mine extended 4 clicks. Install is reverse of removal. Make sure to depress the brake pedal while you insert and rotate into the lock position! Then release the pedal and pull to the full 'up' position. The switch will self adjust! (My brake lights were constantly 'on' until I did this step)
20. Reassemble and reconnect everything else - then go have a beer!