I really like the Bentley repair manual. It is several steps above a Haynes/Chilton. It is the collegiate abridged version of the service manual. Transmission fluid ATF WS fills your hybrid transaxle. Changing the fluid is identical to changing that of a manual gearbox: Remove the fill plug, position catch pan, remove drain plug, give the fluid 5 minutes to drain out, install drain plug, pump 3.5 quarts of fluid into the fill hole, install fill plug. This is a 1/2 labor job for a dealer. No flushing machine, no code reader.