Hello there Changing the password is possible if as you are still active in that recent Thunderbird program that is installed on tha pc with the latest version of the software. Go to the left , yes go down to the left corner where you can use that setting icon gear that has the menu for settings in there and click on it. Click on that icon gear and look for that just appeared searchbar that have do appear on top in the next page to type there the word password and click on enter or ok to search. Look for the text or option in the list to use ''change the primair password'' in the next page that just appeared there and try to click on it and go in and there is a new menu that does appear now you can use that menu there to provide the current password and change that into that new password that you like to have as a new password then. Greetings googlethunderbird.