Before attempting to remove the right side manifold on 5.0L, get the AC system discharged by a professional. Pull the engine cover off the rubber grommets and take the cable off the negative terminal of the battery. Remove the alternator if yours is 4.6L engines and, for the 5.0L engines, if equipped remove the strut tower cross brace. Loosen and remove the front wheel and then support the car properly on jack stands and then take out the inner splash shield of the fender well. Use penetrating oil on the catalytic converter to manifold studs and nuts as well as the exhaust manifold mounting nuts due to rust. The nuts on the exhaust manifolds should be unscrewed together with the catalytic converters and the catalytic converter assemblies should then be relocated to the back. Attach an engine support fixture or hoist, then release the nuts of the engine mount upper. To perform for the left exhaust manifold removal, you will need to take out the intake duct and the air filter housing, pull the connection of the rear heated oxygen sensor, and remove the intermediate shaft from the power steering gear. Lift the engine 1 1/2 inches to provide plenty of clearance then unbolt the eight studs and attendant exhaust manifold. For the right exhaust manifold on 4.6 L, engine, the starter has to be taken off and the front and rear heated oxygen sensor connector have to be disconnected, the transmission cooler tube bracket must also be taken off. In case of a 5.0L engine, such parts also have to be detached: sound enhancement pipe, radiator cover, air conditioning compressor, battery and its tray, rear heated oxygen sensor. Some of the mandatory parts to be pulled out include; crossmember brace, lower splash shield and the transmission fluid cooler tube bracket all of which are located under the vehicle. Pull out the wiring harness retainers and pull also the ground strap of the right side mount alongside the right side engine mount. Once more lift the engine for clearance and unbolt the eight nuts on the exhaust manifold. For installation, inspect the exhaust manifolds to see that they are not cracked and make certain that the stud threads are clear. Place a new gasket and slide the exhaust manifold over the studs but put the nuts first before tightening them from the middle then to the extreme ends to the recommended torque. The rest of steps are the steps in the reverse order that you undertook in the removal and start the engine, look for the presence of exhaust leaks.