Maybe someone could comment on the methods linked by KTL....
First, the methods used by those folks seem to introduce a slightly different pattern than the original if there were any appreciable wear.
Secondly, the distance from pad to shaft bore centerline is shortened, and now if you "keep the same profile as original", now the angle of attack to cam lob is slightly different.
Third, since material is removed by feel, then how do you keep accurate track of how much material is removed on each rocker? I would think you would like to remove a consistent amount from each.
Fourth, does the hardness of the pad surface get affected when grinding?
Maybe Chris_seven will chime in to tell us his solution for determining the pad arc on his rockers, would be intresting to hear.
Also i found this, page 10:
http://www.chevalierusa.com/pdf/FSG-818_C1224CNC.pdf