Step 1: Wash and dry shorts
Step 2: Allow yourself to be repulsed at what they now look like
Step3: Iron hem into the right place (or) pin in place if you are like me and don't (ever) want to iron
Step 4: Using matching thread, sew a straight stitch a fat 1/16" from edge. Make sure you backstitch at beginning and end.
Step 5: Stand back and admire your awesome work
Step 6: Rock your low-maintenance shorts!