I'm not sure the clearance situation is all that much better on the 124.
Instead of the special hex key socket tool, just use an ordinary L-key wrench. Grind off the short end as needed to get the proper length for clearance, and put a short length of 3/8 steel pipe on it for extra leverage.
I also cut my fan shroud in half for easy removal. Cuts are at 12 and 6 o'clock, and zip ties through a couple of drilled holes hold it together. Not 'pretty', but very practical.
1986 300E 5-Speed 240k mi.