Share 'Creating a contour cut line on the inside of lettering??'

I'd like to use my versacamm's cutter function to cut out some vinyl lettering for application on a shirt but I'm not sure how to get the cut lines inside the letters. For instance, how do I cut out the inside of letters P, B, O, etc? I know how to get a cut line around the outside but not sure how to do this. Any help would be greatly appreciated. Thanks Kevin