Go to your MB dealer and get the cluster-pulling tools. They're just a few bucks, and worth it.
Then, you hook them in behind the top of the cluster, and pull it out. Replace ALL the bulbs while you're in there.
Now, I have done W202 and W210, but not W124. Might be different. This topic is covered many times in the threads. Do a search for your chassis #...
1998 C230 "Black Betty"