You should go to a laboratory or to a machine shop that specializes in making machined items from carbon blocks. This has to be done in a specialized building or room which has a dust control system and even then you must wear a suit that will prevent you from being coated with the carbon dust. A respirator is needed while performing the work. Machines normally used are band and cutoff saws, milling machines and lathes.
It is one of the dirtiest jobs on the planet.