A special tool is required to stop the fan clutch from spinning so that you can remove it.
I bought the tool, but someone else may know how to improvise something. Perhaps someone out there has a picture of that little slot the tool sits in?
Even though I have the right tool, I decided to cut the shroud into 2 pieces for easier access. I made cuts at 9 o'clock and 3 o'clock.
I then drilled holes in the shroud to receive a wire tie on each side to hold the pieces together. Not 'pretty' but this has worked great for me, and been a big time saver.
If I ever were to decide to 'go back', a new shroud is like $20, so no big deal.
Best of luck,
1986 300E 5-Speed 240k mi.