Via the Users area in Team Learning

How do I add users?

Just click the user's full name

Provided you have permission, just click on the Edit User link

Yes, you can use the "Move User" function

Yes you can do this via the user profile of the manager. Just click on the plus (+) symbol in the Direct Reports section

Provided you have the 'Course Enrolment Administrator' permission you can enrol team members in courses that your company has licensed through Medcast

Users in the Team Learning system must be assigned at least one manager. This can be any user who is a member of any System Role where "Is Manager" is set to true, or the manager can be set to "Self" in the case that there is no suitable manager to be assigned.

You can deactivate them but it's a good idea to check for any direct reports.