In order to cut the platter, you will need either a fine-toothed band saw or a dremel with a cutting wheel. Make sure to wear gloves and goggles, as the platter may shatter. It doesn't matter where you cut your slot, but make sure it is as perpendicular to the tangent of the point you picked. Make the cut as straight and narrow as possible. Begin the cut from the outside of the platter, traveling inwards. You may choose to cut all the way through, or leave a little material for stability. I cut mine all the way through without any issue.