To remove the exhaust manifold, first disconnect the negative cable from the battery and securely raise the vehicle on jackstands. Apply penetrating oil to the exhaust manifold fasteners and let it soak. The process is similar for either side, but the air cleaner duct must be moved, and the EGA pipe disconnected by removing two bolts and separating the EGR tube from the left exhaust manifold, depending on which manifold is being removed. Support the transmission with a floor jack, then remove the transmission crossmember and skid plate to drop the exhaust pipes out of the way. Remove the nuts attaching the exhaust pipe flanges to the manifold, disconnect the electrical connector at the oxygen sensor (leaving the sensor in the manifold unless replacing it), and take off the heat shield by removing its bolts. Next, remove the exhaust manifold and gasket, noting that engine support brackets are held by two of the exhaust manifold studs/nuts on each side, which should also be removed. Inspect the manifold and fasteners for any cracks or damage, and use a scraper to eliminate old gasket material and carbon deposits from the mating surfaces. If the gasket was leaking, have the manifold checked for warpage and resurfaced if needed. For installation, position the new gasket over the cylinder head studs, install the manifold, and thread the mounting nuts into place. Tighten the nuts from the center out to the specified torque, then reinstall the remaining parts in reverse order of removal. Finally, run the engine and check for any exhaust leaks.