To remove the intake manifold, first relieve the fuel pressure, disconnect the negative battery cable, and drain the cooling system. Next, disconnect the fuel rails and lines, capping them to prevent dirt entry. Remove the throttle body and label all wiring, vacuum, and coolant hoses connected to the intake manifold. Take out the camshaft position sensor and remove the pushrod from the number three cylinder intake valve, loosening the rocker arms on 2006 and later models to remove all pushrods, marking each for reinstallation. Remove the manifold attaching bolts or studs using a Torx driver bit, noting their locations for reinstallation, and then take out the intake manifold, prying carefully between the manifold and block while avoiding damage to machined surfaces. Clean all traces of old gasket material from the mating surfaces, lightly oil threaded fasteners, and apply RTV sealant at the intersections of the cylinder head and block. Position the intake manifold gaskets over the tabs on the cylinder heads, install the front and rear manifold end seals, and apply ATV sealer on top of the end seals without allowing it to dry. Carefully lower the manifold into place, install the bolts and studs while tightening them in the specified sequence, and if the thermostat housing was removed, install it with a new gasket. Complete the installation by reversing the removal steps, refilling the cooling system, reconnecting the battery, and running the engine to check for vacuum and fluid leaks.