My windshield seal is old and has cracked and separated from the roof somewhat, causing water leaks into the driver side footwells. For now, I treated the gap with a Silicone II sealer to minimize rain-related leaks, but it's only a temporary solution. Ultimately, I will need to have that seal replaced.

I searched the forum about this, and I found a few threads about this, but my questions is somewhat different. I have NO experience whatsoever replacing windshields or their seals on ANY cars. I would only give the car to an MB dealer to have this job done to make sure they put all the OEM materials, but I'm sure it will be expensive... What would be my chances of success if I decided to undertake this job myself? What sort of skill is necessary for this?