You will need to speak to Xbox to see if they can recover the account, if they cant then your setup cannot be altered and is permanently stuck as-is Bungie will not step in and unlink accounts nor will they deactivate cross-save for you. [quote]I forgot the login to one of my accounts linked for Cross Save. Destiny Player Support and Bungie cannot modify or remove accounts linked to Bungie.net profiles. To protect player privacy and data, you must be able to log in to any linked accounts to prove ownership prior to modifying your linked account. If you no longer have access to a linked account, you will need to reach out to the specific platform’s support for assistance with account recovery options.[/quote] https://help.bungie.net/hc/en-us/articles/360049498031-Destiny-2-Cross-Save-Guide