I have done something easier and also doesent make bottleneck on the splitted usbs.
I just take an old usb cable and cut it, then just go to the cable of the reader with the internal usb. Then just cut both and solder the wires colour by colour. Everything works like a charm. I proffited one port wich can be used for external watercooling to make it arrive to the I/O pannel, connecting it on your preferred usb port, wich if i remember they are 10; 2x intel 3.0+4xmarvel 3.0+4xintel 2.0.
Also i had done the same to make a ROG link cable.
i7 4770k delidded | Maximus VI Formula | 2x8Gb Gskill 2400 | HD4890 CF | NZXT 820