To add a NEW person to your directory as an admin, go to Manage Users / Add User. Enter their email and first and last name. Then check all the boxes and click save.
To give an existing user admin security, go to Manage Users / Edit User and search for their record. Double click on it to bring up their security profile. Check all the boxes and then click save.
Manage Data = change any type of data and settings and pay invoices.
Message Directory = email or send a notification to the entire directory.
Message Group = email or send a notification to a class or grade (a group within the directory).