I have pulled the steering wheels of other cars and it wasn't that hard. I don't have experience with pulling MB steering wheels so I won't even start with advice for that. However I have pulled out the instrument cluster on both my car and father's W123. I'll admit it would of been easier with the wheel out of the way, but it's not absolutely necessary. For my car I just grabbed the top edge of the cluster and pulled it out. For my father's car I removed the lower dash panel and pushed from behind. The cluster will only come out so far due to the oil pressure line and speedometer. These are easy to remove. I would recommend using a back up wrench for the oil pressure line, this is one fitting you don't want to strip and cause a messy leak. The beauty of the instrument cluster is that all the connectors on the back are all different so you can't put it back together wrong.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section