Turn the carpet upside down so the bottom of the carpet is facing up. Locate the threads holding the outer coil in place. Cut the threads with a seam ripper. Continue cutting threads until you have loosened as much of the carpet as you want to remove.
Cut the loosened coil off with a sharp pair of scissors, leaving 10 inches of extra coil so you can sew a new finished edge. Discard the removed braid.
Loosen the braid in the 10 inches of coil that you left on the carpet. Re-braid it 7 inches, getting looser as you go. Tuck the last 3 inches under the carpet.
Sew the loose 3 inches of the coil to the back side of the carpet with needle and thread. This will keep the finished braid from unraveling.
Turn the carpet or rug over so the bottom is facing down, and place the carpet where you want it.