You need to change the password and username for security. Let us take a look at the steps Arris router password change.
Steps for how to change Arris router password
Login to your Arris router.
Click on security and utilities.
Go to default settings and chose the option to reset.
Wait for a few minutes and the reset would be completed.
Enter the default credentials which are as follows, username : admin, password : admin.
Now, go to settings and choose and new password and click ok.
Read more: arris sb6183 firmware update