Do you mean the wheel shape? Like this one? http://www.thegearpage.net/board/sho...d.php?t=897720
You use a straight rod (my EBMM and SBMM basses came with one) that will fit in the hole, an allen wrench, or whatever in the holes and turn right or left.
Just be careful not to scratch anything up and if you go too far through the hole, the rod will drag on the wood underneath the wheel.
I actually think this is a much better system than "regular" allen wrench adjustments.
All the best,
SBMM Ray35, Ibanez ATK300, Fender Modern Playa Jaguar, Squier VM Jazz V, Mesa Walkabout Scout
Last edited by Bobster : 01-12-2013 at 12:40 PM.