I'm assuming you know how to unpick stitches? If not get an unpicker tool and I'm sure there will be videos on the net. (or approach a female or male who can sew properly and ask advice - could be a good pick up line - wink.) Essentially just be sure you are only cutting stitches not cloth. And don't cut with scissors. If for some strange reason it is all weird underneath you'll need to save patches to reattach.