Heater core r&r 66 barracuda with ac

Anyone have a link to how to replace the heater core in my 66. It has AC,but Don't know if it's factory or dealer added, it does have the under dash unit. I have the glove box out and plan on removing the front passenger seat and radio. It is my understanding I need to drop the whole unit, but the AC portion is not connected, is that correct? Couple of questions.
1. Do I need to remove the fan motor, if so does it come out from under the hood.
2. other than the bolts in the engine compartment, and the J bolt in the passenger side air vent, are their any other fasteners keeping the unit from dropping down?
I appreciate your help. I have rebuilt motors, manual transmissions, fabricated race cars, but this project has me a little freaked out. It is an original 32K mile car, unmolested, and I don't want to screw something up that I can't replace, like the rubber hose going from the heater motor to the cowl. If I need to remove the heater motor I know it will be toast. Thanks for reading, any feedback will be much appreciated.thanks