is this 3.0 litre v6?
are you intending to replace both rocker cover gaskets or just one?
On this particular engine the rear bank is a bit difficult to acess you need to remove the Intake manifold to get to it.
So there we go There are several bolts holding the manifold on, and from memory you need to unplug some electronic connectors (tps isc etc) and the throttle cable, and some small coolant hoses. Its not really difficult but can be a bit fiddly
Just be careful not to damage any plugs and be careful to not damage the intake manifold gasket (also watch you dont drop any bolts etc down the intake ports when the manifold is removed i would suggest putting a rag over them)
Once the manifold is removed you will find it is super easy to acess the rear rocker cover and also replace the spark plugs in this bank