It's a pretty easy job, but you do need 2 tools to keep it easy. The 1st is something to hold the clutch which Ismalley already gave you a good option. I used a metal rod (about 1/4" in diameter) that I bent the end. The other is an Allen wrench or socket to turn the fan nut. The clearance between the fan and radiator is minimal. I'm not sure, but I think it was an 8mm Allen.

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07 E350 4Matic wagon, 06 S430 4Matic, 99 SLK 230
retired W210 (x3), W124, W126