If you are designated as being a co-instructor to a course in Patriot Web, both names will appear automatically in Blackboard Courses. You can also add them as an instructor manually.
Go to the Control Panel under Course Management (bottom left side of the page).
Select the option for Users and Groups and then Users.
Select the green button Find Users to Enroll.
Enter their username (their Mason NetID).
Choose the role you want them to have.