Hi Mike, I removed it a long time ago but think it's easy once the coolant hoses are disconnected. So...no dash or dash top removal needed, but removing the padded trim piece on the bottom corner buys some useful clearance for hose access.
There is one 1/4-20 screw or bolt on each end of the housing that fastens the unit to some hanging brackets behind the glove box. Captive nuts are built into the evaporator housing. I'm not aware of any fasteners on the front edge of the unit (nothing in my parts bin at least) but it would make sense - seems like the assembly will be unstable without additional support.
There are two holes shown in this pic where 2 small dia. fasteners COULD be used. Anybody have screws here extending up into the dash? Any other fasteners used?