I need a diagram of the heater core to remove.
heater core removal on 2002 Ford Mustang GT
This is quite an extensive repair that requires removal of the dashboard and evacuation of the air conditioning. I would at the very least get a repair manual, try alldatadiy.com, they have an inexpensive online subscription that should provide all the info you need. Good luck, and leave yourself plenty of time to complete this job!
how hard is it to replace heater core