Thanks to all who contributed--just did this today. Used 12 qts of fluid (after reading about 1 billion threads on WS vs other fluids, I ended up going with Valvoline Max Life--I think 16 quarts shipped from Wally World set me back about $65), plus a bit for topping off when i got to the level check step.
Some notes: 5' of 1/2" i.d. (5/8"o.d.) clear vinyl tubing were plenty for routing as in @2001LC 's photo above. Wasn't hard to keep it nice and far from the exhaust, and it is a tight enough fit in the refill port that there was no chance of it slipping out mid-process. Didn't spill a drop. From there, anyway.
I drained the pan and refilled with ~2 quarts, then removed the top rad cooler line (needed my Lisle pick to get the hose to come loose as I tugged on it) and connected 4' of 3/8" i.d. clear vinyl tubing that, and ran that down past the corner of the engine "skid" into a gradated Home Depot bucket.
Had my wife turn the car on and shift through the gears until about 2 quarts were added to the bucket each time. I usually was able to add around a quart as it ran, but would have her stop it as I ensured I had added a full 2. At one point, I got carried away and overflowed my funnel (hanging from the hood as in the pic above); guess a towel like @2001LC is using would've been a good idea.
After draining and adding roughly 12 quarts, I used my OBD scanner app to determine fluid temp (123 degrees), which is good for the fluid test. On first opening of the level hole, nothing came out--closed it up and (duh) added about a quart. Which apparently ALL came out on second opening of the level drain . . .
Other than me overfilling the funnel (which was over my head as I had the truck front up on ramps to make it level) and over correcting for low fluid, all went great--thanks all.
PS--totally unsure if this needed doing Toyota records show a drain and fill not long before I bought it, but I figured it was probably just a pan-drain and fill, but the fluid really didn't look bad . . . oh well, at least now I know it's right.