Hi there!
In order for you to disable and unlink any accounts from your profile, you need to be able to authenticate the accounts. Bungie cannot remove these links as they would be treated as unauthorized.
I would contact Steam Support to see if they can provide assistance. For more information, please review the below help article.
https://support.steampowered.com/kb_article.php?ref=4650-SDKC-0716
English
-
Thnx.