So I looked around for info on changing the V6 3.6L spark plugs but there is nothing! Everyone just recommends waiting 100k miles (as described in the owners manual) but I don't feel comfortable with that. I drive about 25k miles annually so I feel I need to service it more frequently. Anyways, here is some info that should help you along.
Weapon of choice. No gapping needed. About $7.50 each.
^ Pop the hood
^ Pull off the decorative engine cover. No tools needed, just manly hands.
^ Remove air intake ducting. One hose clamp screw on each end (flathead screwdriver), unplug one senor near the throttle body, and there is one plastic standoff on the passenger side that you can lift up on. It should pop off easily, very similar to the engine cover plate.
^ Pic of support piece to the left of the dipstick. Just lift it up. The sensor you need to unplug is circled in red.
^ Picture of engine with no decorative top plate or intake duct.
^ Another view.
^ Closeup of the standoff with the rubber cap missing.
^ Remove the 7 upper intake plenum bolts. They stagger/zig zag all the way to the firewall. I believe I used a T10 torx bit but you can use a regular socket head. It might have been 8mm.
^ Last bolt location for intake plenum.
^ Unclip these from the intake plenum. Squeeze with your fingers.
^ Remove the two nuts from the side of the intake plenum. My wrench is on the first nut. There is one to the right hidden under the plastic/near the big tube. 10mm wrench.
^ Remove two 10mm nuts on the throttle body side. This photo shows my wrench on one of them. There is one more nut more towards the firewall. Use a flashlight to see in there.
^ This photo is now with the intake plenum loose. There is a huge foam "insulator" piece on the drivers side that just lifts up and out. You will need to remove it to access the coil packs/spark plugs.
I believe it was a 12mm socket that is used to undo the coil pack bolts. In the last photo, one coil pack has already been pulled (all the way to the left) and the other two just have the bolts removed. Inside that big silver hole is the spark plug. You will need probably a 6-8" extension PLUS a 5/8" spark plug socket with the o-ring built in to hang on to it. Do not use a normal 5/8" deep socket!
I torqued the new spark plugs about 1/4 turn once they got snug. The coil pack bolts take very little torquing. The intake manifold bolts also take very little torquing.
Hope this helps someone out there.