NAT Type Help.

[MERC767]

Hello I have two Xbox consoles in my house both are wired and I want to find out how I can make both of their NAT types open. One of the two is already open but I cant figure out how to make the other one open as well. I have a Linksys E2000 router I used port range forwarding to make my Xbox open and i gave them both static IP Adresses please give me a step-by-step instructions on how to do it if possible thank you very much!