Quote5 – Once removed, this reveals dirt, grease and what is a tired bearing behind an old bearing collar (Fig5a). The bearing collar is removed (using tool A.5.0187PF – see Fig5b) after it has been released from where it is peened into the hub carrier. Note, that depending on which side you are working, the collars have either left or right-hand threads.
Some cars are not this spline style nut, but rather an internal hex. My '78 GTV, '82 GTV and 2 '88 75's all had the hex style. I've never actually seen this spline or key nut that uses the special tool in the middle of the following picture.
(http://www.dep-o.co.uk/tech/replacing-alfetta-rear-wheel-bearing/attachment/img_7064-2/)
I have machined up a tool before to work with the hex nut. I still have it floating around the shed. If you want it, let me know and I can go find it.