So, the saga continues....

I have taken out the dash and other various pieces of equipment and can see the heater core. Covered in Rust colored dust from the water leak is a strong indication it needs to be replaced. As I go to remove it however there appears to be a bar controlling the flaps obstructing removal. Here are my questions that I hope someone can answer.

Has anyone done this before that can tell me if I need to remove the heater box?

Do I need to drain the AC and open the system.

Do I need to remove the steering wheel?

Diagrams I have indicate that there is a retaining bracket (I think it is hidden in front of the dash and behind the firewall) that has screws that need to be removed. How would I gain access.

Seems like a lot but I have to admit this is frustrating as I can see, touch it but can't seem to figure out how much of the car to disassemble to get to the thing.

Thanks.

PS: It is a plumbers nightmare, the more you work on the drain, the more stopped up it becomes!