Note: The A/C system was properly discharged by a proffessional before I started this project!

Trying to replace the evaporator in 97 K1500. Got the bottom plastic off and got the heater core out, but I can't figure out how to get at the evaporator. All lines in the engine compartment are disconnected. I've checked several times to make sure all bolts are out, but the second piece of the housing that covers the bottom of the evap (the part with the evap drain on it)seems stuck towards the bottom. I've tipped the dash back and can't seem to see anything there that would loosen it up. Any and all help is appreciated!
TIA
Dave