timing chain on 2002 Mercedes-Benz S600

I just need to know some tips, recommendation and or proper techniques on how to set the timing chain during removal and installation of the timing chain as this is the most critical step in changing the head gaskets.

Asked by for the 2002 Mercedes-Benz S600
I can't do this subject justice in this format. You need to find a manual and study it. You need to know the torque procedure and a few other things.
Here are two sources for you:
For AllData:
Here's the one for Mitchell as well:
If this is no good, buy one. It's worth it. I wouldn't touch this engine without a good manual, myself.