For a writeup, here is what I sent Zakk to pick up after the front clam is off. I wrote it up myself, so it is subject to errors and the fact that more shoddy people have worked on this car in the past than you'd believe. I literally pulled a French Toast stick out of around the heater core once...
1) Drain coolant. Maybe. You'll spill a ton either way since you can't drain the heater core, so I didn't bother. If you have something to cap the coolant lines as you remove them (Saran wrap and zipties work great) then that's probably easier overall than having to refill all the coolant.
2) Drain AC by cracking a line if you didn't have the foresight to have a shop do this before tearing it down. I let it trickle out overnight so I didn't lose as much oil
3) Remove the elephant trunk going from the blower to the interior diverter
4) Remove any electrical connector you see. You'll have to pop a protective cover off of the heater control flap to get to its connector
5) Remove both lines to the AC dryer (black cylinder) and then cap the lines
6) Remove the expansion valve by loosening the Allen screw on top in between the two lines. This will release clamps at the top and bottom, and it all comes apart. Cap these lines, too.
7) Remove and cap the coolant lines running to the heater core. If you cap both the lines and the connections at the core, it might be less messy.
8) There are two metal latches that hold the blower to the heater core, so pop those loose, and remove the bracket that runs fore/aft holding the heater core assembly in place.
9) Now the fun part. This is how I did mine, so your mileage may vary. I rotated the heater/AC core out (counterclockwise when looking at the car from the front) and basically flipped it upside down to get it back out.
10) Once you are done swearing and have the heater/AC core out, the blower fan pops out pretty easily.
11) The resistor pack is on the bottom and should be straightforward. I didn't use a kit, so I have no idea what you'll have to work with. Just make sure the new pack is mounted such that it gets airflow or it will overheat on the lower speeds.
12) Installation is pretty much the reverse, just watch for the edges on the heater/AC core since they can catch on the way back in. You'll also want to pour coolant/water directly into the heater core to replace any that was lost or else it'll be a bitch to bleed. I regret not doing this...
Upgrades - I pulled out some of the ducting for the footwells and cleaned that up. I also cleaned the chassis with some pontoon boat cleaner. I replaced most of the foam pieces since mine were deteriorated. I also used clear silicone to seal the seams around the plastic boxes since they were leaking out air something awful. This was probably the single biggest improvement.
Also, hooking up a heater core bypass solenoid is a massive upgrade for the summer, but that is only slightly easier now then later on.
"Lots Of Trouble; Usually Serious"