If you are serious about doing it yourself, check out www.pindelski.com. Mr. Pindelski posts photo tutorials about how to repair and replace many things on your benz. His subscription is about $25-30/yr. and is WELL worth the money. He also will respond to questions with expert advice. He has never taken more than half a day to respond to any question I have posed to him. Check it out... well worth the money! The chain rail replacement is covered, and I believe he shows you how to fabricate a pin-puller with garden variety hardware store parts.

Good Luck
--Jay Swann