On my '89 190E there are no clips retaining the cluster in place that I recall. I unscrewed the speedo cable and pushed the cluster out from behind. There is a rubber seal that surrounds the cluster that keeps it in place. You can also use a plastic tool (not metal, it will scratch) to pry the cluster out alittle bit at a time from the front. Just enough so you can get your fingers behind the front lip and then pull it out further. Pull it out enough so you can get our hand behind the unit and unplug the remaining connectors.
I believe I removed the steering wheel to make it easier, but with some manuvering, I believe it can be removed while in place. I could be wrong on that one. It had been a year or so since I had mine out.
'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)