What image are you using? If you use the one from the SPI (with out SD card) you can just run the commands as well as the image for the SD that you can download from here https://communities.intel.com/docs/DOC-22226. You can find this into your Linux image in the /sys/class/gpio also you can test it works for you by turning the LED on and off with the commands:
echo –n 3 > /sys/class/gpio/export
echo –n 1 > /sys/class/gpio/gpio3/value
echo –n 0 > /sys/class/gpio/gpio3/value
If that works you can follow sergey’s blog and you shouldn’t have any problems, the possible errors you might get are when it says invalid argument is when you type a non-valid value, if you get a device or resource busy is because the port has already been exported. I hope this helps you.