you actually don't have to change the oil filter. On the newer GM's all you have to do is change the paper filer that leads to the oil filter. You can get the filters at a Chevy or GM dealer or at an autoparts store. Once you do that it should have instructions on how to change the paper filter. I think the filter is located at the top of the engine, near the windshield on the drivers side. I would also recommend getting a Chilton or Haynes manual for your car. It will tell  you everything you need to know.