Don't have a 94, but for an 85, the easiest way was to remove the blower and reach in for manual extraction of leaves, etc. I also used a shop vac to suck out anything else that I could not manually get. I think I then used a garden hose with nozzle to spray down the evaporator and check that the condensate drain was functioning and not blocked.
I re-used the goo that seals the blower motor to the housing. If you cannot, RTV will work, or you can use latex caulk, or the 'rope' stuff from an auto parts store. It does not take a lot to seal.
Check the blower motor bearings for rough or stiff turning while you have it out. It's old enough to go for a drink at a bar, so some attention now could save from future problems. The motors are not readily openable to add lube to the bushings, but you can dribble some oil down the wheel end/output shaft to get onto the bushing. I have drilled an access hole on the other end to drip in some oil and then plugged with a dab of caulk.
While totally under the hood, you can remove the three panels, well two and a wiper motor, and gain access to the intake plenum. Most times it will have enough decomposing leaves to start a garden. There are 'flap' drains at either end that can get blocked with decaying matter, and cause the rainwater level to rise above the rim of the intake leading to the blower chamber. If the flaps are plugged.
tom
