I replaced the spark plugs yesterday and thought I would share my steps to help out anyone who has not tried this before. My Haynes manual states to remove only the upper intake manifold but I ended up removing both the upper and lower intake manifolds as a unit. First, I disconnected the battery negative terminal. Then removed the airbox and air tube. Then I disconnected all the throttle body hoses and plugs and removed the throttle body. Then I disconnected all the remaining hoses and plugs going into the intake manifold including the fuel line where it goes into the fuel rail. Some coolant dripped out of the hoses.

I unbolted the power steering reservoir and moved it about an inch away from the intake manifold. After spraying the the EGR tube with Liquid Wrench, I used an adjustable wrench to loosen the nut. Removing the throttle body earlier improves access to the EGR tube. It was very awkward to get a wrench on the EGR tube nut.

There are 8 bolts which attach the intake manifold to the block. The bolts are captive and do not separate from the intake manifold but are simply loosened. I lifted the intake manifold straight up a few inches then slid it towards the driver side and out of the car. The rear spark plugs and coils can now be easily removed. This is a good time to also replace the PCV valve. I replaced the 6 odd shaped gaskets on the bottom of the lower intake manifold. I vacuumed the loose dirt from the valley area where the intake manifold mates with the block. I cleaned the valley with brake cleaner applied to paper towels and also the areas around each of the 6 intake passages, being careful to try to avoid dumping dirt down into the holes.

Installation is basically all the steps in reverse.

 

Thanks for sharing your experience.