The video is simple but clearly explained. I saw it once before. I presently have 101k plus miles on my 2009 DTS and I would like to change my plugs. I bought the car used at 97k miles and dont know if the plugs were changed before I bought it. It idles perfect and I have no codes but would like to keep up with the recommended scheduled maintenance.This video is pretty helpful if you haven't seen it yet. Shows what you are up against for the rear four. BTW, that's where the rubber fuel line comes in real handy.