You will need to go to your email provider and change it there too. Ordinarily, I'd expect that if you had changed your email account's password, the old one stored in Thunderbird would stop working, and Thunderbird would ask you to fill in the new one. So ideally you shouldn't need to know how to edit a stored password. However, here is how to do it In Windows. (The menus are slightly [http://kb.mozillazine.org/Menu_differences_in_Windows,_Linux,_and_Mac different] in Macs and Linux.) In the old fashioned menu across the top, it's under: '''Tools|Options|Security|Passwords→Saved Passwords'''. In the new menu application button on your toolbar, it's under '''[≡]|Options|Options|Security|Passwords→Saved Passwords'''. Once there, after setting it to reveal passwords, you can edit it in situ by double-clicking on it. Note that in general a password is stored twice, once each for incoming and outgoing. You usually need to change both instances.