Here is a DIY for spark plug replacement. If your coils need changing, use this DIY as well.
Hope it helps others.
This is a simple maintenance item. Dealer will charge upwards of 500 dollars. you can do this spending about $60 on plugs, and few hours of time.
Think how much beer money you will have left over.
If you don't normally work on cars, expect to take about half day. Still real easy to do, just take your time, don't rush.
If you do other DIY stuff on the car, I would estimate 2-3 hours with cleaning.
Subsequent replacement would be about an hour and an half at most.
Wobble extension needed for the job, to remove rear most plugs (cyliner 4 and 8.) Those are the nearest to passenger and driver.
The way to use it is to plug wobble extension into plug socket, then plug in extension into the wobble, then insert that into the hole. Then attache ratchet and loosen up.
Follow pics in their order and look for instructions in them.