How to chang my oil in my 2004 C7 Cat 330

You don't list a coach name so location or the oil filter will vary. Mine have always been up inside the frame rails close to the engine and there will be only one oil filter. Depending on the manufacturer of your coach you will also have one or two fuel filters. The oil filter is large and you will need a big strap wrench in order to get it off. When I changed my antifreeze on my Cat there were drain points in the hoses running up to the heater core in the front of the coach and I used those to drain my system.