As I posted last, I ordered a 80W 12v extraction pump from Amazon. I set it up, warmed the oil (ran the engine until the coolant was 190F, so perhaps the oil was warm enough???), and ran the extractor.
I started at 11am, and finally extracted about 3 quarts after an hour+ (you have to rest the pump for 15 minutes after 20 minutes of runtime), which left enough room for my 5-6 quart drainpan to catch. The I went underneath.
At first I thought to remove the plate under the oil pan, but I couldn't even get the nuts to turn, even using a 1/2" electric impact (corded), or a 4 ft breaker bar. I was wanting to inspect the hidden pieces as well as gaining clearance for oil drainage. Exasperated, I decided to just remove the oil pan plug, and found it to be almost as tight as the aforementioned bolts. At this point, two hours into a 15-minute oil change (my usual time), I gave the drain plug bolt all I could (just using my longet 17mm box wrench, fearing more power might strip it out), and it finally turned.
It fought me all the way out, getting finger-tight at the last two threads, and the oil drained into my drainpan (held up in my other hand). About 4.5 quarts came out, and made no mess, but I replaced the original drain plug with a new magnetic-tipped bolt from Amazon
it went in much better than the other came out (I checked for leaks after filling with oil).
How hard is the underside plate to get off? If it would come off, then I could've used two pans (or a larger one), and been sure that oil wouldn't spurt on top of the plate, causing a mess. Extracting 3 quarts reduced the pressure enough to where the remainder just stayed vertical. Total time to change oil: 3.5 hours, including cleanup. Way too slow.