You can unlink your account by: 

• Launching the Game through Ubisoft Connect or Steam
• Clicking on the "Unlink" Button located at the lower left corner of the Main Menu.
  • You will be prompted to unlink your account.
  • There will be a confirmation screen for safety that follows the unlinking step.
• You can also unlink your account using the "Logout" button located in the in-game menu.