Need help with 97 Lumina 3.1L Heater Core

Can anyone help me? Ive removed the 10 or so small screws on the heater core cover, but the cover has, I believe, the condensate tube molded into it, and this tube protrudes through the firewall. On the engine side, there is a semi-transparent tube protruding out about 1 inch, with a little rubber slotted cap slipped over it. I've tried pulling from the interior side (not REAL hard) but to no avail. Any ideas? Thanks for listening.

Don't know but maybe seeing it all might help?

Here's a link to the part numbers

http://www.gmpartseast.com/chevy/components/1997-lumina_ac-heater-module-asm-mw090260109-l82m131wm69.html

http://www.gmpartseast.com/diagrams/large/18W/ac-heater-module-asm-mw0902601.png