1973 Charger heater core

Hi folks,
My 73 Charger Rallye sprang a heater core leak. It is not a factory AC car.
I would like to remove the heater core before I buy a replacement. Service manual is not very detailed.
Wondering if it is possible to get to the heater core without removing the whole heater housing (plenum).
I'm guessing it's not possible, but I thought I'd ask anyway.
Thanx in advance.

unfortunately, the box needs to come out, then disassembled to r&r the core.

Even if it was posible to remove the half box ( which I think it is ) it makes no sense and would be harder try to keep just the other half of the box attached to firewall. Better to remove the full box and dissasemble the box on bench.

Is easier than it looks... just need to dissasemble the glove box lid and liner to get more room, and remove nuts from engine bay side of firewall, aside the hoses of course. Dunno if the heater box can be pulled out with blower still attached, but on 71/74 B bodies the A/C box is posible.

Thank you for the responses. I have a Strato Vent plenum from a 1972 Charger I used to own. The heater core might just be the same if I'm lucky.
Otherwise, it might be the time to take the leap and install aftermarket AC once and for all.