Connecting Airport Express to blu-ray player with ethernet

I cannot seem to be able to configure my Airport Express to be used as a wired internet connection to do firmware updates etc on the Blu-ray player. I have an Airport Extreme to connect it with. I easily did it previously with Airport Utility, but somehow lost the connection and can't figure out how to get it back. I have tried many times starting from scratch with a hard reset of my AE. Does anyone know of a walk through to get this done? I am pretty experienced with all things Mac, but this has me frustrated. I have no problem setting up Airtunes with the AE.

thanks

wired connection =extend a wireless network
wireless connection = join a wireless network
then set the same things up as you did on the extreme except name the express another
name and I find that if you bring it over to the computer and hook it up for the setup it
will go a lot easier. I used DHCP for both on mine if you used static give it a different ip address.

Actually I found out the problem was the Airport Express was an older one that operates at 802.11g. My Airport Extreme is a 802.11n and doesn't see the g. Way around it, but it slows down the wireless. Got a new Express and it works fine and fast.