To carry out the removal of the exhaust manifold, one should first pull of the cable of the car battery in the negative terminal then, upstream oxygen sensors should be removed and must be taken from the exhaust manifolds in order not to be damaged. Then, on the note, jack up the vehicle and position it on suitable jackstand supports. For the front manifold, it is required to uninstall the exhaust manifold heat shield, while for the rear manifold it is necessary to remove the alternator and, if there is an exhaust gas recirculation tube, to unlock it from the EGR valve. Remove the outside four gasket surface sheet metal bolts which fastened the catalyst exhaust pipe assembly to the exhaust manifold, apply penetrating oil to the fasteners before, and then remove manifold from cylinder head by fastening six bolts. To install the system, the mating surfaces should be free of any previous gasket, and the manifold should also be for dents, crack, or warpage by placing a straight edge on it. If so needed, someone can take the manifold to an automotive machine where the surface is reworn. Take off the exhaust manifold inner heat shield or gasket, then with a new heat shield/gasket put the manifold firmly against the head and tighten the bolts. After proper alignment place the mounting bolts at the middle and then rotate them clockwise till the torque is reached and then vice versa from the middle outwards till all the mounting bolts reach the required torque. The last components should then be refitted in reverse sequence, before cranking the engine in order to look for exhaust gases escaping between the manifold and cylinder head as well as the manifold and exhaust pipe.