94 Jetta GL- Heater Core!!!

How easy is it to replace the heater core in a 94 GL?? is this the model where the firewall blocks it? or is a "pop out/pop in & reconnect" deal??
I have to make a final decision on purchasing the vehicle by this weekend, and I can't seem to find ANYWHERE online (short of purchasing a manual) the process for replacing the heater core!! is there anyone who can help me? i appreciate you taking the time!!! :)

I've only worked on 88-92 style. It's a major chore that requires removing the dash. You may contact Smitty at sasponline.com about the 94, He's an excellent mechanic and I buy my parts from him.