It's no different than adjusting the axle position using the two puny bolts and some shims. Instead, the arm bolt is all the way to the rear of the socket and you extend the arm to find the position you want.

Professional alignment is very desired during or after this operation, as you affect the steering geometry a great deal. I had this done on an alignment rig...

 

yeah ill be sure to get an alignment afterwards. now im all giddy to order them and finish building this axle