At last my '92 400E needs a new fan clutch.

The price of the part is

Can anyone comment on the level of effort to replace this part? I've done several fan clutches on the 617 motor which was quite easy but never on the M119. The car has a new radiator that I'd rather not remove in the process.

Everything is somewhat harder on the 119, especially in the 124 body due to tight quarters.

Thoughts? Tips? Comments? Any special tools required? I've seen a very stubby 8MM hex on a long flat wrench that looks like it would be quite helpful.