Instrument cluster removal
This is how to remove an instrument cluster, demonstrated on a w126 S-class, but this basic principle applies to nearly every model up to the year 2000. The steering wheel does not need to be removed to do this, there is just about space to remove the whole cluster with it in place.
The dash cluster is only a push-fit and isn't secured in place, but is a very tight fit. Ideally you need a pair of dash removal hooks to use (as pictured below) but if you don't have these you can remove the panels under the dash and push it out by hand from behind, although access is very limited and it can be very dificult.
Use the dash tools to reach between the instrument cluster and dash edge, gentle insert and twist it 90 degrees so that it hooks behind the edge of the dash. You then need to gently wiggle the whole cluster forward bit by bit. Some clusters (particularly those on the w140 s-class and R129 SL) are prone to the plastic front cracking, so ultra care is needed. Once the dash is loose you can squeeze your arm behind it and start un-plugging wiring. On most models its the speedo cable that's holding the dash in tight, this is a screw fit, remove it and the cluster will come free.