1. Disconnect negative battery cable. You'll be working near the airbag and last thing you need is it going off on you.
2. Unscrew the 3 screws under the glovebox that hold the hinge on.
3. Open the glovebox and push in the sides, which will allow you to remove it completely.
4. Remove the plastic shielding from the under the dash. There will be one screw, and also a quick-connect nut you have to remove.
5. Unplug the 6-line vacuum plug (it will get in your way)
6. Unscrew the black plastic cover. There are two screws on the left, and two on the bottom.
7. Pull off the cover, it's kind of difficult to remove, take your time.
8. Pull off the hose clamps on the two heater core hoses on the firewall. The hoses are a PITA to get off. I found the best way to do it is to grab the end of the hose with pliers and rotate it back and forth while pulling it off.
9. Now go back inside the car, and unscrew the screw that holds down the heater core.
10. Put on some gloves (The core is sharp) and pull it out. Take it slow and work it out, there's not a lot of room to do it.
11. Put the new heater core in, make sure the foam lines up correctly, and install in reverse order.
12. Start the car with the cap off, and fill with antifreeze until full.
13. Replace the fill cap, and bleed the system.