I linked the wrong Google Classroom™ teacher account to my Realize teacher account. How do I unlink or disconnect the Google account so that I can choose my correct Google Classroom™ account? 

Go to your Settings page and select the Disconnect button in the Connected External Accounts section. Once you take the action of importing a class, and you subsequently disconnect your accounts, the class(es) you previously imported from Google Classroom into Realize will no longer sync with Google Classroom. 

If you no longer need the classes that were imported, you can manually hide them. If you share a Google imported class with a co-teacher, please be aware that when you disconnect your Google account from Realize, you will no longer be able to view the Google-imported class. However, your co-teacher will still be able to view the Google-imported class within Realize.

Disconnecting an account from Google will also disconnect classes. Any assignments that were synced from your Realize class to your Google class will be deleted.