Assuming that it is the same procedure as on our 95 C220, you can buy a tool from the local MB dealership that you use to pull the cluster out for about $20. The tool consists of a pair of T-handled steel rods about 6 or 8" long that are bent 90 degrees at the end and cut off approx. 1/4" after the bend. You could probably make a set yourself but note that I did not find clothes hanger material to be strong enough.
Friction is the only thing holding the instrument cluster in the dash. You stick the steel rods on either side of the cluster between the bezel and the leather surround (carefully!), turn so that the 1/4" protrusions on the tool grab the back of the cluster and pull straight out.
It is important to be very careful and controlled so as not to break the glass of the cluster on the steering wheel. On the C220, many have written that you have to remove the steering wheel on non-telescopicing wheeled cars. I assume that your higher line and newer E300 has the telescopicing wheel. If so, make sure it is fully extended. In any event, I did NOT find that the steering wheel had to be removed to replace the bulbs in the cluster on the C220. Just be careful.
As far as changing the bulbs is concerned, they are in plastic, twist to unlock and pull, sockets. It helps to have small hands to get to them and small fingers to remove them. The bulbs are available at the dealer. I believe that they run $2-$3 a piece.
Hope this helps.