1999 Ford Escort A/C Evaporator Removal

I am replacing the a/c evaporator on my zx2. I have removed the glove compartment and removed the air bag. I have almost disconnected the dash. My thing is... I cant seem to disconnect the metal fittings under the hood that go into the firewall that lead to the evaporator. I looks like one metal pipe fits into the other but no matter how much force I use.. i cannot budge it loose. Can anyone provide detailed instructions or possible photos on this?

Thanks in advance.

Tony