Heater Core Removal

Yeah, mine's a 68 and has the A/C box. I wish I could just use a regular non-A/C box to simplify things. All I know is the heater core leaks and I have a new one I'd like to install. Looks like a real pain in the butt. Do I just undo the nuts in the engine compartment and disconnect all the cables and hose on the inside?