Short diy tutorial on changing the spark plugs on W221 Mercedes S class.
All you need is T30 bit, a torque wrench, a regular wrench, 6 new plugs and about an hour of your time.
Some recomend using grease on the threads, some say don´t put any stuff on new plugs. I didn´t use anything and all works fine.
As I am not professional mechanic, there might be some misstakes in the shown proces. Do this at your own risk. Also, I will be happy for constructive suggestions and advices.
Have a great day, guys.