If you want to change the password for an email account, you need to do that at the email provider's website.

I don't understand your question. If you're trying to change your Mozilla account password, here is an article telling you how. https://support.mozilla.org/en-US/kb/how-change-or-reset-your-mozilla-account-password If you are trying to change the password for your email account, you can't do that from within Thunderbird - you have to go to your email provider's web site to do that. You can then, knowing your new password, change the stored password within Thunderbird to agree with it. Here's an article describing how to edit saved passwords: https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-tb If you need more help, please be more specific as to what your intention is and we can give you some more details. If you're looking to change your email password, tell us what version of Thunderbird you're using, what your operating system is, and who your email provider is.