If the name stays the same and you only need to change (update) the stored password then fill the name in the login form and let Firefox fill the wrong password. You may have to press the Tab key to fill the password field. If you replace the wrong password with the new password then Firefox should offer to store the new password. Use the ''Remember Password'' bookmarklet on websites that use "autocomplete=off" to prevent Firefox from saving passwords. You can verify that Firefox has stored the new password: Firefox > Preferences > Security: Passwords: "Saved Passwords" > "Show Passwords" If that didn't work then remove that name and password and Firefox should offer to save the new password on the next visit or if you refresh the login page. See also: http://kb.mozillazine.org/Password_Manager http://kb.mozillazine.org/Deleting_autocomplete_entries