I finally managed to find a neighbour who know how to take the screen out at a time I wasn't crazy-busy or exhausted or on my way somewhere.
I've put it in the kitchen, since this is a not-quiet one I got from my mom, who had ductless a/c installed, and thus shouldn't need window a/c any more. It's not as loud as the other one, but not as quiet as the LG one we put (pretty permanently) in the basement bedroom last summer. If I can't keep my whole apartment cool with just this one and some fans, I'll buy an LG one for my bedroom. (The bedroom and the kitchen are marked as being on separate circuits.)
So... now that I have this installed, either the whole summer will be cold (or at least nicely cool at night so that I don't need the a/c), or way hotter than this unit can handle. Winnipeg: I'm sorry for whatever wacky weather Murphy and I cooked up.