Welcome to TN!
Unless they updated the 2008 manual, it's wrong anyway. (The 2007 manual's instructions don't work)
I believe the process is:
1) turn trip odometer to the A reading
2) turn off vehicle
3) turn key to the accessory position (or push the start button once with your foot OFF the brake if you have the smart-key)
4) push the trip-odometer switch/stalk in and hold it until step 7.
5) turn the vehicle on
6) the display should read that the system is resetting - it takes about 5 seconds.
7) when the display says complete, you release the trip odometer switch/stalk.
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FYI: Not to be sarcastic, (many new TN'ers don't realize) there is a search button for the forum. This topic has been covered a few times, so in the future if you have questions make sure you search before posting- you might find an answer to your question much faster- and avoid some sarcastic words from some of the members on the board.
Hope this helps, and again, welcome!