They are delineated in the CPs. I don't have access to my CPs right now---so can't tell you which one----a fairly early one though---maybe somewhere around 30. There is a template in there (be careful if you have a pdf of this---so that the template prints out to the right size). It also tells you where to install on the wing.
Or you could cheat and go to Aerocad and buy premade vortilons (if they sell them anymore) that you can almost immediately stick on with silicone. If the area between Aerocad's vortilon does not exactly match the curvature of the wing, you can tape your wing (or whatever favorite release method you like), then tape the vortilons on with a generous amount of micro between the wing and vort. Let it dry, pop them off, carve the base of the vort to a pleasing shape, then stick them on with silicone.
