I have not needed a special tool or even a screwdriver to remove the instrument cluster from my 190 or 300E, so far anyway (it is not to say that yours is not stuck). Simply tug on both ends, try to "rock" it if you will (it is held in place by a clip on each side) and it should come out enough that you can reach behind it and spin off the speedometer cable (be careful not to oversterch the cable though because it may not work after, I did learn it the hard way, after a couple of hard pulls had to change the speedo cable). Then the cluster will come out some more so you can remove all the electric connectors (by the way they are all different and designed so that they go on one way only so can't mix them up :-)don't you just love german engineering!)and those little warning lights at the bottom. The bulb for the light comes with the socket just twist and remove. By the way there is a fuse at the back of the cluster I beleive it is red in colour the same twist type as the light bulbs. A competent shop should not charge you more than 1/2 hour labor for this, as I can do it in less then that.
Hope this helps.