To remove the exhaust manifold, first disconnect the cable from the negative terminal of the battery, ensuring you have the correct activation code for the radio if it has an anti-theft system. Next, raise the front of the vehicle and support it securely on jackstands, then disconnect the oxygen sensor electrical connector for specific models and detach the exhaust pipe from the exhaust manifold, applying penetrating oil to any difficult fasteners. Remove the heat shield by taking out the bolts while soaking them in penetrating oil beforehand. After that, remove the exhaust manifold nuts and detach the manifold from the cylinder head, ensuring to also remove the bolts from the lower brace near the flange. For installation, discard the old gasket and clean the gasket mating surfaces on both the exhaust manifold and cylinder head with a scraper, followed by a rag soaked in lacquer thinner or acetone. Position the exhaust manifold on the cylinder head and install the nuts, tightening them from the center outwards to the specified torque. Finally, start the engine and check for any exhaust leaks between the manifold and the cylinder head as well as between the manifold and the exhaust pipe.