> I have loosened the nuts holding the two hoses to the unit, but they
 > didn't easily come out.  I am hesitant to just yank hard as all is
 > attached to that flimsy plastic shell.  Any tricks or pointers here.

On the "rear" housing you can remove the top plastic (something like
10-12 screws). This will gain you access to the evaportator, and you
should be able to get a couple of wrenches on the hoses more easily. I
didn't have any trouble separating them.

 > In addition there is a small metal tube that a sticker calls a MOSTAT
...

Yes, you don't want to cut that. That's the thermostat which allows you
set the temperature that the AC cools (and causes the compressor to
cycle). Once you have the plastic off the top of the rearward section,
you'll be able to easily pull the thermostat out of that section. Just
put it back later when you are mounting this in your vehicle.

 > Any other useful tips as I go to remove the hoses and the wiring?

The housing is held in place with screws. And while there is some
reinforcement with metal, now is a good time to try and fabricate some
additional support so as to not crack the plastic. With the top off the
rearward section, you'll be able to see the metal brackets that give
partial extra support.