They never made a 300Sd in the U.K. so i am assuming the 300SD is the same body as the 300SE, 420Se, ect,.
If so, Mercedes have a special tool to do this. it is possible to improvise though. Get a thin piece of metal like a welding rod, and bend the last 5mm(not sure what that is in inches) into a hook. Then slide it in between the Cluster and the dash anywhere down either side. Twist it once it is in so the hook grabs the clusters edge (it is designed with a lip for the hook to grab), then pull.
Some clusters are tighter than others so it may be tight. it may also be wise to make two hooks and try to do both sides together.
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