Well if you dont mind doing some cutting in there then i have a bit of a shortcut for ya.
You dont have to pull the whole dash out of the car, but it would be easier that way.
Ok, if you read in the manuals about this job, they all say the AC evaporator casing has to be pulled back and off of the firewall from inside the car. This means taking it to a shop before and after the job to have the AC discharged and recharged again. I didnt feel like doing that.
The reason they say it has to be pulled back is because you cannot reach the back 2 screws holding the cover of the heater core casing without doing so. It is wedged right underneath the windshield support area.
You can however access the front screws.
So what I did was remove the front screws, and then as far back as my dremel could reach, I cut the top of the casing. This allowed me to access the heater core to pull it out and replace it without touching a single AC component. I just used a little epoxy and duct tape (after all, HVAC ducts is what this tape was made for in the first place) to seal it back up after I was done. Everything has worked perfectly fine from that day.
Well except for when i was messing with the return line from in the engine bay and BROKE the tube off the heater core and had to do it all over again, but thats a different story
good luck with it, and umm, well i would say have fun, but it won't be fun in the least bit
-Drew