I have found for most things, particularly electronics and automobiles it's crucial to go to an expert when needed.
When ever there is something that comes up that I am unable to do I go straight to my local MB specialist. These cars, like most cars today, are very special in many respects. Mercedes more so than any other car I've owned.
For my MB and my subaru I will only go to an expert.
I have found non-specialists can complicate even the simplest issue and cost 10 fold by the end of the day.
If you have the CD you sould check out the list of tools alone these guys/gals need to properly service an MB. I bet a properly outfitted MB garage would have at least $10,000 in MB tools.
These people are worth every penny, like anything else, the more times you do something the easier it gets.