Now that all of that crap is taken care of, back to the deconstruction
Remove all visible bolts from the heater unit. Some are under the hood and some are under the dash! There is one down between the firewall and inner fender and is really hard to get to, but can be done without removing the inner fender, you just have to feel for it.
These bolts are under the dash on the passenger side, the one on the lower right is the nut that is on the firewall between the firewall and inner fender.