Seconding this. It can be done, but is a major pain to do so. The little part of the cord that's broken has 2 different even tinier wires inside (in addition to the unbroken cord next to it, which also contains 2 tiny wires). Both wired need to be separated and repaired. You'll likely need to very carefully cut off the little plastic strain relief piece there (this in itself may be quite difficult to do without causing further damage). After removing that piece, the individual wires need to be separated and individually repaired, probably with solder and heat shrink tube. Soldering stuff that small isn't easy and you'll definitely need to get some spare material to practice on if you haven't done it before. Then add a larger piece of heat shrink around both repaired wires. Rebuilding the strain relief piece might be tough, but doable if you build an epoxy mold for it or something.