Reach360 - Change learner's role from Learner to Manager

Hi, 

I am new to Articulate and its products. I am trying to change a learner's role from learner to Manager in Reach360.

I uploaded the learners with the CSV template; all worked, but the default role is learner. How do I change it to Manager? I can only edit the learner's name and surname and add a group. The Role field is greyed out.

Please advise how to do it.