If you changed the settings and credentials but do not seem to remember them. Here are the steps on how to reset Arris router to factory default. Let’s take a look at the steps.  Turn the router off.  Press and hold the WPS button on the router.  Switch on the router back.  Power light on the router should be on.  Now, release the WPS button.  The router will reboot automatically. You can log in through the default username and password.