Here is a simple guidance to flash your OpenWrt firmware to the router

OpenWrt firmware can be download here:

downloads.openwrt.org/snapshots/trunk/ar71xx/openwrt-ar71xx-generic-gl-inet-v1-squashfs-factory.bin

downloads.openwrt.org/snapshots/trunk/ar71xx/openwrt-ar71xx-generic-gl-inet-v1-squashfs-sysupgrade.bin

1. Connect your computer to the LAN or WAN port using internet cable. Leave the other port unconnected.

2. While pressing the RESET button, power on the device. You will see the GREEN LED flashing.

3. Hold the RESET button until the GREEN LED flash 5 times, the RED LED will light up. Release your finger now.

4. Change your computer’s IP address to 192.168.1.2 manually netmask 255.255.255.0. E.g. in Windows 7, refer the attached picture to set your IP.

5. Visit 192.168.1.1 using your browser, you will see the following web interface.

6. Click “Choose File”, choose your own firmware, then click “Upload”, and then wait unit your new system boot up.