I purchased an 02 Chevy Duramax last year and had the oil changed. I guess the oil change signal was not re-set. I do not have an owners manual. How do you re-set the change oil signal and how many quarts does it take for a change as I will do the next change myself. Thanks for any reply.

You turn the key on but don't start it and push the accelerator pedal to the floor 3 times in 5 seconds, then turn the key back off... Should reset it. It takes 10 quarts or so depending on if you prefill the filter at all.. I always put a little in even though it's a sideways mount filter... Put in 10 and run it and then check the level. Add as needed.
If you want the part that tells you about changing the fluids and stuff on the duramax go ask the dealer for the diesel supplement, the owners manual only covered the gas motors. The diesel supplement is a seperate little book that tells more about your diesel motor.