5.2 Magnum fan clutch
Air chisel or "spanner" wrench.
Might get lucky with strap wrench.
Spanner wrench is at Advance for about $35.
Lisle has a kit with spanner and 36mm "big" flat steel wrench head that accepts a 1/2 drive breaker bar.
Kinda spendy at about $75, and kinda wobbly to work with, but good to get torque with once you get it on.
BTW, I've seen two different hole pattern on the pulley face for the spanner.
The Lisle tool has both, and actually fits three or four different patterns.