forgot my gateway password

Hey

i currently own a XB6-T modem/router but i want to implement my own router since im getting a spotty connection in one of the parts of the house... i went to 10.0.0.1 and for username i put in admin and for password i put in password but it still says incorrect password for the username  now i have tried to reset my modem/router by pressing the reset button on it for a few seconds untill it reset, i also tried restarting it from the xfinity website but i still cant log in i even. whaat else can i do here ???