[Shotimes] Heater core?

[Anthony del-Busto]

I am currently experiencing antifreeze smell in the passenger compartment,
misted/fogged windshield, and coolant  coming out of the drain immediately
under the lower A/C line on firewall.  Is this a texbook symptom of a
leaky/failing heater?  If so, how difficult to replace?  Has anyone
attempted this task?  If so, any tips?  Unfortunately, all of this started
to occur on recent roadtrip.

Thanks.
Tony
93mtx, 89k, stock