Just a small wire is required to go from the led ground pin to another ground point on the board, I used a ground point from usb as it was easy to solder on to. See image for mod (ignore the wires not in the red boxes a these are for a switch mod I added).

Hope that helps those who were missing their led not working.
For a more advanced mod so the LED goes off when you turn the box off from the remote, you can disconnect the positive side of the LED from the board and put a wire from the leg to the 5v pin on the usb socker - although you should put a 330ohm resistor in line so the LED lasts a long time.