Is it possible to unbolt the centers
 

myself off of the Volk GT-C wheel? Anyone know what tool to use? Gonna have them either powdercoated or polished.

I do not have Volks but, I have always been told that you should not dismantle 2 or 3 piece wheels yourself. If it was any other part, I would do it but, a wheel coming apart at highway speeds is not good.

I wouldnt think so. There are just too few bolts on the GTCs for them to be only bolted on. I believe the bolts are there only to contribute to the 2 piece look. Look at other 2 piece wheels that use fasteners to secure the pieces. They use many many of them.
I dont know for sure but I would pretty much bet on it.