Only Administrators can change a users 'Role Permission' by going to the People Directory and selecting the individual they would like to update.
First, go to the user and next to their name select the 'Edit Profile' button. See below:
Next, scroll down until you see 'Account Type' and here you can select the 'Account Type' you would like to change to:
Lastly, select save!
Remember:
Members: can create meetings, polls, discussions, upload documents and view all activity to groups that they are a member of.
Observers: can participate in groups, discussions, polls, and meetings that they are invited to.
Administrators: have all privileges including billing information, ability to change plan type, adding people, account settings and updating announcements.