When I did the chain and rails on my wife`s car (190e), I recall the pins being a bit of a pain to remove. If you had some sort of slide hammer you could grip the pins with, that would be the best way to go. On her car they were a pressed (tight) fit. (I had to replace one because the guide had shattered and the chain cut partially through the pin!) I ended up getting a grip on it with a big pair of vice grips and using a carefully placed J shaped pry bar underneath to pry up. It worked. The replacement pin came in one length, so I had to cut to the length I needed.