What I used to loosen the nut was a boxed wrench and a pair of vise-grips.
Jammed a long screwdriver between the vise-grips to hold the shaft while I loosen the nut with the offset boxed wrench.
I don't know wtf was Nissan thinking when they re-designed the top hat without a slot to ensure when it gets installed or removed?
You can just remove the nut without the shaft spinning.
Thats how they were on my 70 240, 74 260, 90 300ZX.
I was really shocked to see they removed it.
Glad to hear at least its done.
