Cadillac Repair: heater core replacement, heater core replacement, heatercore

Question
Thanks to a question that was answered by you on this website in the past, I was able to self diagnose my Caddy and find that the heatercore needed replacing. What steps do I need to take replace that part? Are there pictures?

Answer
If you are mechanicaly inclined or know of someone who is, You will need picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.

I need to know the following:

YEAR of vehicle:

Model of Vehicle:

Engine size of vehicle: