If you have an Xfinity Router and want to use the Xfinity admin password , you need to first connect the router to a computer either wirelessly or using an Ethernet cable. Once connected, follow the series of steps mentioned below: Open a web browser on your computer. Type the router’s IP address in the browser’s address bar, and click on “Login”. Once you click on the “Login” button, you can enter the router management console. Access the various tabs to make necessary changes to the router settings. Once you change a setting, click on the “Apply” button to save the changes.