It's "half-change" because the 4.5 quarts (4.25 liters) in the transmission pan is only about half of what's in the transmission. But what a difference! Shift quality is greatly improved! I bought five quarts of fluid and a crush gasket to replace the one under the drain bolt. It was probably original factory equipment, as was the fluid since it came out as dark brown as motor oil. YUCK! The Santa is an '01 so it was past time for the change.

Material:
Five qts fluid, part number 00232-19012     List US$9.62 each
One gasket, part number 21513-11000      List US$1.26 each
The dealer gives me a break on pricing, so they cost me a total of US$36.63 with tax.

Tools:
24mm socket for the drain bolt
12mm socket for the splash pan bolts
Suitable ratchet handle or breaker bar
Jack and jack stands
Drain pan
Long neck funnel
Disposable creeper (a cardboard box flattened - gets me off the asphalt and makes moving around easier)

Removing the splash pan underneath the front end is necessary to reach the drain bolt and let the fluid drain directly into the drain pan. Total work time was an hour, including putting a couple of miles on the car to warm the fluid so it would drain better. To say it was easy is an understatement. I worked under the master bedroom window as the wife was sleeping late on a Saturday morning. She said she didn't hear a thing. Of course, I spilled an ounce on the car port, so a minute with the garden hose will take care of that.

A little time spent for a good return. I'm planning to do this again once or twice with oil changes to further renew the transmission fluid.