To install and remove components, it is important to start up by ensuring that safety measures are observed particularly in fuel injected models where it is important to release the fuel pressure before unscrewing lines. In the case of 2.2L engine, this can be done by disconnecting the choke and air bypass valve cables, removing air cleaner or cross over vent, disconnecting the PCV valve, and removing the cam cover, cleaning all gasket surfaces, and then installing new gaskets and tightening bolts up to appropriate torque. In the case of the 2.6L 1987-88, the negative battery cable should be disconnected, the air cleaner assembly, and hoses removed and then the rocker cover is unbolted and removed using RTV sealant and then installed and screwed back on again. In the 1989-93 model, disassemble the battery ground cable and accelerator cable, disassemble the air intake pipe, and wipe down of mating surfaces and fit the rocker cover with a gasket or RTV sealant. In the case of the 3.0L engine, it is necessary to disconnect air bypass valve cable and PCV valve, remove cam cover, and fit with new gaskets and tighten the bolts accordingly. In the 4.0L, looseness battery cable, de-pressurize fuel system, and strip required parts to gain access to rocker cover with due caution of draining coolant. Once all the surfaces are cleared, put the rocker cover back in place with a new gasket, put the bolts back to the required torque, and reconnect the battery and make sure the engine has no leaks before starting.