To register for a CBE you must first contact your student advisor so they can add the CBE Registration Acknowledgement form. This will go over important information and requires a signature. Your student advisor can upload this form into your student portal documents under the My Documents tab.
After you have successfully submitted this form, and it is approved, you can reach out to your student advisor to register you into the course shell (study materials).
To read more about CBE's available take a look at What CBE's can I take?.