I just did the rail replacement on a 94 C220. Took about $250 in parts, including ~$40 for the special lub. Took me no more than 3hrs. No special tools. However, I had a subscription to alldata and spent some time studying before hand. Bought the parts described in a technical bulletin found under the sunroof topic. The parts were bought from a dealer in MD that advertises in the "Star", Valley Motors, and they can be found online. This was the metal sunroof, but the instructions are there for the glass roof repairs in alldata. If you are the least bit handy and have the time save yourself a little money.