[Roadsters] Heater core replacement question

[Michael Knorr]

My '66 began overheating with a lot of steam coming out of the heater core. I
assume I have to replace the core, correct? And none of my service manuals
describe how to remove and install the core. Is this a big pain to do? Does
the core just pull out, or do I have to yank a bunch of other items before I
can remove it? I also assume I have to remove the box that the core sits
inside of. Is that correct? That's the box the dash heater control is attached
to. I'd appreciate any advice you can give me.

Regards, Michael Knorr'
1966 SPL311-03639