To begin working on the upper intake manifold, you must first relieve its fuel pressure as well as disconnect the battery. Then, take off the engine cover, breather hose, air intake duct, accelerator cable, and throttle body connections. Take away the intake manifold cover together with the upper intake manifold also if it is there remove the spacer plate. Mount a new gasket and then attach a new spacer and finally fix up the upper intake manifold by tightening all nuts and bolts in place. At this point reconnect your battery and check the coolant level before moving to lower intake manifold. After that remove upper intake manifold together with fuel rails then take apart two lower intake manifold sections.