First reset the AE by holding in the small button while plugging it in and continue to hold it for >15 seconds. The light will change color and flash. Then use the setup utility and designate it as a client. Viola!
Apple is amazingly weak on their instructions for how to use this with anyone elses gear, but this is all you need to do.
Apple is amazingly weak on their instructions for how to use this with anyone elses gear, but this is all you need to do.