First, mark the line to be cut. A sharpie works well for this. In my case, I was marking what would become holes for 1/2-inch bolts, so I traced the outline of a socket with a diameter of approximately 9/16-inch. Next, using a center punch and a hammer, mark that outline with small divots every 1/8-inch or so along the line. Finally, trace again over the now punch-marked line with soapstone.