1. Change the IP address of the router to an unused static one on the network (Make sure you are not duplicating the IP address of an existing router).
2. Setup the SSID and encryption keys (make the same as your other AP if you have one and wish to extend that network)
3. Ignore the WAN port. The WAN port is not used.
4. Turn OFF the DHCP server on the router.
5. Connect a cable between one LAN port on your network , to a LAN
port on the router. You may need a crossover cable. Make sure
the front panel lights are correct for the ports when you plug in the
I setup a Linksys Wireless N router using these instructions.