I had a persistent mildew smell the last few months, so I finally bit the bullet
and researched the options. One suggestion from OctaneJunkie was to
remove the blower motor, and I think that does allow access, but I found a
way to actually clean the core, not just spray something on it. I don't have
fan noise, so I didn't pull the blower, but it's probably not a bad idea anyway.

Two Philips screws gets the glove box, then 3 10mm bolts for the support
crossbar. Pull out the heater vent tube, then remove the blower resistor pack
and the core itself is visible from that hole.

I put a plastic pan on the floor under the evaporator to catch overlow. Fill
the cavity with foam. I used Klima Cleaner, though I'm not sure it's any
better than the Frost King or Lubeguard cleaners. Even after two cans, there
was still a web-like film on the core, so I used a long HVAC brush to knock
as much off as possible. I couldn't get it all, but the smell is gone, and it
does cool better.

Button everything back up, run it for a while in the drive before getting on the road.

Attached Images

 

what is that black hose with a foam wrapped around it?

No idea. It's a screen cap from here. I wanted to show the core.

This is mine.

Attached Images

 

Actuator cable for a manual blend flap. Auto HVACs won't have it.