Connect gargoyle router to computer using regular cat5 cable. Leave router off.
Under Firmware Download → Atheros → x.x.xx
sudo ifconfig eth0 192.168.1.2 up cd ~/username/Gargoyle/trunk/fon-flash ./fon-flash-gui
I had to enter my password at this point for the network to be detected. Select the downloaded files in the two drop-downs. I had mine on my desktop so they don't have to be in the same directory. Click on the Flash now button at the bottom. Plug in the router and wait. There will be a popup telling you it was successful when its done.