RE: Changing sparkplugs on the 4.0 Pacifica
From the service CD
Always remove the ignition coil assembly by turning the assembly 1/2 turn and pulling straight back in a steady motion.
1. Disconnect the negative battery cable.
2. Remove engine cover.
3. Remove the intake manifold, (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL).
4. Prior to removing the ignition coils, spray compressed air around the coil area and spark plug.
5. Disconnect electrical connectors (1).
6. Remove the ignition coil (3).
7. Remove spark plug.
Sounds like a big job. No plug wires ... each plug has its' own coil and the plugs are inside a "plug tube" which is under the manifold. WOW.