Replaceing Spark Plugs

Does anyone know how I can access (2) of the spark plugs that are buried on the backside of the engine in a 2001 Nissan Quest? There are (3) on the front end which are easily accessible and then (1) to the left side that is hard to reach, but once the ignition wire is pulled loose, I can get to it. The (2) on the back end are nearly impossible to access.
ANy ideas?

Use a long extension and a flex neck socket to reach them. If you can you could also go from the bottom with the same tools.