Viscous fan package?

I use bolts on mine. It helps to just get the bolts started first - like a thread or two on each. That'll allow you to pull the clutch out in order to fish them all in. Then use an open end wrench and snug them all down one flat a time. It's a shitty process, but it can be done.
Yep. It's been described as "a real pain in the dick!" Pretty much sums it up.