The wrenches are non adjustable , looks like it ,I will take some more pics .Who sells that adjustable spanner? Looks like a Snap-on Blue Point wrench?
the two ways I've done it...
1. an air chisel/hammer
2. two pair of vise grips... one clamped down on the pulley and allowed to 'wedge', the other to remove the fan.
done it many times both ways