I just did the transmission fluid change last weekend. Instead of pouring each bottle of new ATF through a funnel, I just poured all the remaining 10 quarts (after 2 quarts of new ATF were already replaced in the pan) into a 2.5 gallon water/bevarage dispenser (purchased at Walmarts for $7) and connected the dispenser spigot to the transmission fill hole with 5/8" clear PVC. I turned on the dispenser before starting the car. If the new ATF was flowing in too fast, I could just turn off the spigot momentarily and on again when the same amount of old fluid was pumped out. This made the job really easy and clean. I don't know how Lexus does not recommend changing ATF as part of the maintenance schedule, but at 90,000 miles, the fluid came out pretty dirty (blackish brown in color).
I also did the coolant flush, power steering flush, brake bleed and brake rotors/pads replacement all in the same day. Thanks for all the info provided by great forum members.
htd4555