I had mine done by the local BMW dealership. They charged 3 hours plus an alignment. But they did put markings on the GC plates showing -3 Deg and -1.5 Deg.
Very easy to adjust at the track: 5 minutes per side. No realignment needed yet after 8 track days.
SOLD...E92 M3, Competition Package, MDCT, Ground Control Adjustable Camber plates, StopTech 380 BBK, OEM exhaust mod