I had the perform maintenance light come up on my display of a 08 Mega w 6.7 diesel. I figure it is just a standard triggered by the miles. What is it that they do during these maintenance's? I assume I can do most of it myself. I am new the the cummins so I dont want to go to a dealer and get taken for a very expensive ride. Suggestions? Is there a good service manual for the 6.7 cummins?