I'm in the process of replacing the heater core on my '83 300D. I have the dash and the center console off and am at the heater box. I loosened every attachment point I can see, but I am stuck, the heater box doesn't seem to want to budge. I have a rapair manual, but unfortunately, it doesn't go into this type of repair. Now that my interior is in pieces, does anyone have any hints?? HELP???!!!!!

There's a bunch of wiring attached to the front of the heater box that I haven't removed. I was hoping that the box would come off and I could just push it aside without detaching the wiring and get to the heater core. There are two strap type attachments that I loosened, but no luck.