Dear Spotify, please let me unlink my Facebook account
I already unlinked my Spotfiy account from Facebook with this way: https://robblewis.me/convert-spotify-facebook-to-email-login...No account migration of contacting support is needed. Just use your registered email account to reset (or in this case actually set) your account password and afterwards you can log in via your email+pw. Then in the Spotify preferences the button to disconnect Facebook becomes available.