Heater Core replacement on 1991 Audi 100

A diagram is needed so I can remove and replace the heater core in a 1991 Audi 100 sedan

Asked by for the 1991 Audi 100
You can find great repair manuals with step-by-step instructions, diagrams, parts locations and other important information here: http://www.eautorepair.net/Marketing/Default.asp?VID=125669
I wouldn't start without it, it's not a simple process.