Hello Mary,
OK, I found it. There is a mistake or misunderstanding in the description.
It says 'As an administrator, access the student's profile, open Preferences and click the Permissions link.'
It should be 'As an administrator, access the student's profile, open Preferences and click the Assign roles relative to this user link'. Because under permission, there is no option to assign roles.
The rest is OK, I modify the text.
Thanks again,
Phil