How to Change the Password on a Modem
If you want to change the password that you've given to your wireless or wired computer network, you'll have to do so using the "Settings" application built into your modem-router. A combination modem-router both accesses the Internet and simultaneously makes it possible for multiple machines to connect to the Internet.
Open your Web browser.
Type the IP address of your combination modem-router into the address bar and press "Enter." The IP address of your combination modem/router will be listed in the documentation that came with it. You can also find it by clicking on the link in the "Resources" section of this article. All modem/routers from the same manufacturer will have the same IP address.
Enter the user name and password for your combination modem-router.
Click the "Security" tab.
Replace the information in the "WEP Password" box with the new password you want to give to your device. Make sure to write the password down, because you'll need to give it to anyone who wants to connect to your network.
Click "Save." This will save your changes. Exit your Web browser.