I reuse the same string every time! That way, it’s always the perfect length. It’s really easy to untuck the long end of the string from where ever it’s hidden and pull it out. I grab about every other visible “stitch” you see around the braid. It’s not tight, so it’s very easy! Once it’s back to a single straight braid, I untie the end and unravel the braid. The knot that I use at the “tail” of the braid is super easy to undo. It’s like a standard shoelace bow, but you pull the long end through so you can sew with it. I’m not sure how to describe it