Seeing as the link is done on ubisoft's side you would have to contact their support about recovering the account.

If you don't have the info to do that your are ♥♥♥♥ out of luck.

You have to recover the ubisoft account, and hopefully not be as careless with accoubts as your teenage self was.

As mentioned the linking is done in the ubisoft account, so you have to access it to change that. Ubisoft won't make changes to an account you can't prove ownership of.

Aside from that, unlinking wouldn't solve the problem. The games associated with that account are tied to it. A new account wouldn't get you access.

https://www.ubisoft.com/en-us/help/ubisoft-account/account/article/recovering-access-to-your-ubisoft-account/000111797

You have to recover the ubisoft account, and hopefully not be as careless with accoubts as your teenage self was.

As mentioned the linking is done in the ubisoft account, so you have to access it to change that. Ubisoft won't make changes to an account you can't prove ownership of.

Aside from that, unlinking wouldn't solve the problem. The games associated with that account are tied to it. A new account wouldn't get you access.

I'm in a similar position as my account was hacked and the email on my Ubisoft was changed to something else - I had 2FA as well so I don't know how they did this. Ubisoft want me to access the new hacked email account ot prove the account is mine? I have no idea what the new email address is now. This seems pointless. I am avoiding Ubisoft games going forward. It seem steam should offer you an option to delink an Ubisoft account from your Steam account as their protection (Ubisoft) is not as good as it should be.