Signals Notebook: How can a system administrator gain access to a user group if the only administrator has left the organization?

As stated in the article Signals Notebook: Is it possible to grant access to user groups through the security policy, it is not currently possible to grant access to user groups through the security policy. Therefore, as a system administrator, how can a administrator gain access to a user group if the only user group administrator has left the organization? 

Answer: Once a user has left the organization, you can deactivate the user and reassign their content. You can reassign this content to yourself or to another user so that you can later be granted access to the desired user group. 

The following article provides a step-by-step guide on how to deactivate a user and reassign that user's content Deactivate a User from the Signals Configuration.