So first off Leo3000 and cowlitzcoach, thank you for your advice. Leo3000: I ended up following your advice and finishing my objectives, and I related to your choice of words about fooling
with the radiator. Cowlitzcoach: Thank you for the thorough response, all new information for me and it gives me a lot to think about. The "do not leave the system dry" is a little disconcerting, so I'm hoping for your opinions regarding what I did.
I guess my first question is, do these look like shutoff valves to you? They are screws that are about 1 inch long, with fixed wingnut heads on top.
Your opinions matter a lot, but I went ahead and assumed they were shut off valves, screwed them down and proceeded with my work.
Despite my commitment to drain the radiator, I did not watch a youtube video, like I probably should've. I just assumed the radiator drain would be similar to an oil drain. Inconveniently, I found this under the radiator which supported my half-witted logic.
I was disappointing to unscrew the bolt to this
Anyway I monkeyed around with this bolt for way too long, and eventually gave up when I lost my temper. I resorted to plan B which was to shut off the "shut off valves" (I'm eager to hear if those are actually shut off valves), and went to town.
Removing the rear heater was easy enough, I clamped the hoses as Leo advised, and pulled them off. The spillage was modest, and promptly wiped up with rag and mop. The front driver side heater was very unpleasant to remove. I dropped a lot of tasteless profanity while hunched beneath the steering wheel, hoping that someone would hear my cry for help and shower me with sympathy - Nana was supportive and patient. Anyway it took awhile but I got her out(the heater).
The passenger side front heater was a little bit easier, and we got her out alright. I did my best to keep the mess contained, but predictably I did spill some coolant here and there. A lot of ragging and wiping went down yesterday, really glad I got a few extra buckets laying around.
It's worth noting, that I ruined a lot of radiator hoses prying them off with a screw driver, I think it's within my best interest to replace the hoses when I reattach the heaters, including the ones that go to the engine block, I don't think this will be too hard- but I also hardly have a clue to what I'm doing. After I disconnected everything, I stuffed all the open holes with plastic bags to avoid bugs or something crawling into the hoses (my gold standard of logic in action).
The front drivers side heater out, with stereo related cables in the plastic crate above it.
The front passenger side heater out.
The front area without heaters, drivers seat, and electrical console
A close up on my wire bucket carrying most of the wires from the electrical console
A selfie with me and the electrical console removed Wednesday night: happiness level 70%
A photo of my makeshift shop table with two sawhorses I got for $5 and a wooden door I found in a dumpster.
I'm expecting to leave this setup as is for about 3 weeks, so I can insulate and re-wood the flooring before reconnecting the heaters (with new hoses). Do you guys think it's okay or am I risking damaging some part of my bus? I eagerly await your opinions! Thanks everyone for all your help so far.