You should use a scan tool to retrieve the percentage of remaining engine oil, record the remaining engine oil life, loosen the PCM harness connector bolts from the center of the PCM harness connectors, remove the PCM harness connectors from the PCM and the PCM retaining bolts and nuts, slide the PCM away from the intake manifold past the mounting studs and remove PCM from the vehicle and remove the PCM mounting studs from the intake manifold only if replacing the studs.