A cutting tool assembly including a bit holder having a forward portion, a rearward portion, and a generally planar mounting surface between the forward and rearward portions. The forward portion defines a front aperture having an axis inclined relative to the mounting surface, and the rearward portion defines a rear aperture open to the front aperture. A cutting bit is mounted in the front aperture and includes a rearward end accessible through the rear aperture of the bit holder rearward portion.