Kills me as I recently fixed 3 separate lighting cables at the power converter end, but took no pictures! You have to razor the seam around the outside of the case, split the case apart by pulling out with pliers in the cord-wrap flap area (careful don’t split it) and then attach a new cord to the solder spots on the circuit board, or just to the wire stubs. Best to just order a replacement cord as these include the little stopper that fits into the case between the halves. If you’re good at solder-joining cables you can just do this and shrink-wrap ‘em, but I prefer to use a little crimp joiner, and then fill the crimp with solder before sliding the shrink-wrap down over it. It’s tricky because the join has to fit a small space inside the case. You can get replacement cords at AliExpress. I use duct-tape to tightly close the case in case of more repairs.