It is hard to say whether it is hard to do without knowing your abilities but .... if you have some tech ability (sounds like it) and you understand how to do it, and you take your time, it isn't too bad a job.
I ventured into the sunroof on my wagon and 190e. Here is the link to the wagon:
95 e320 Wagon Sunroof: It must be possessed
Try searching using a few key words such as:
300e sunroof tilt
Let us know if we can help,
Haasman