Enter the correct information and Firefox will ask you if you want to change the password or not.

I try entering the new info but I did not get the response if I would like to change my log in info.

You can try this: Tools > Options > Security

and click on "Saved Passwords", then "Show Passwords" and delete the wrong password.

Log-in the website again and enter the correct information.

Please let us know if that helps.