Bungie is not able to remove accounts from your profile. If this Steam account was automatically authenticated when you setup Cross Save, then your browser had that account's credentials cached. In order to change linked account, Cross Save has to be disabled first. You can request deactivation of Cross Save by filling out the form at the bottom of this article. https://www.bungie.net/en/Help/Troubleshoot?oid=48099 If Bungie disables Cross Save for you, you will still need to be able to manually authenticate that Steam account to unlink it from your profile. If you're unable to do so and can't receive help from Steam support, your only other option is to create a new Bungie profile and move the accounts you can access to that one. Doing this will result in losing any redeemed emblems. Also note that deactivating Cross Save for any reason will place you into a 90-day lockout period in which you cannot enable it again.