I’m at the moment logging in to meta.discourse.org via my Twitter account, but I want to delete that account. That’s the reason why I would like to change to a native authentication method (e.g. log in to meta.discourse.org via email + pw). Is this possible or will I have to create a new account?
Log in using your Twitter authentication and go to Preferences > Account > Send Password Reset E-Mail. You will receive an e-mail that will let you choose a local password.