If your pants need to be 4 inches shorter measure up from the bottom of the pants 3 3/4 inches. Place straight pins all around the pants leg at this measurement. (Parallel with bottom of pants). Turn under at the pins, take the pin out and pin up. Press lightly, sew with matching thread at very edge, about 1/8 inch. Cut close to stitching and then turn up again and stitch again. This gives a finished seam.