I was helping a friend with his 190D, 1984 auto-tranny car and he did remove the cluster from it. He was adding a revgauge to it.
Anyway, he didn't remove cable from transmisson but he did take out this black vent hose in the dash before he pushed the cluster out. I think he took off the cable from the cluster itself before he did push it out.
I am not sure about this but maybe it'll help you...
'87 MBenz 190E 2,3 8vlv