The fuel filter on your 2004 Buick Rainier should be located on the side of the fuel tank. If equipped, a splash shield may need to be removed. The fuel lines are connected via quick release fittings. GM uses various styles of quick connect fittings. You will need to determine which you have and the proper release procedure. Unless a special release tool is required, only ordinary hand tools should be required to replace your fuel filter. If you have trouble with the quick release and can some how describe it, I can try and talk you through it.