Hey guys any knowledge about the removal of this nut?

You need to make, or buy, a deep socket. 

And its reverse threaded... AND a total bastard to get off.  A 6' bar will help with leverage.

Just curious, how would you stop the shaft turning while you undo that nut with your 6 foot bar attached?.

Thanks guys, there is a special tool for it but they want 300 bucks for it. So i have my engineer mate on it to build me something for cheap

As far as i have looked, to get this pully off you need a deep socket and a tool to lock the pulley while you undo it, bith tools you can buy for about $500 aus. Im not going to spend that much on this pulley. I will let you know how i get around it.

Having someone apply the rear brake has been enough for me luckily.

cant see why a ring spanner cant be used .. at least just to get if off anyway .

the nut appears very thin [ compared to average nuts thickness] a socket or ring spanner would need to be well fitted to get a good bite.i have various sockets turned down to eliminate the recess that gives poor contact depth for some of my specific jobs,reckon a ring spanner would have about the same depth recess as a socket.but worth a go though.

I'm with Hoody, I made my own tool though, fucking dear little bastards.

Correct tools are a must.