The Roles card provides information about the role (along with the scope) assigned to the user. User can see assign roles and resources, by clicking Change button. The Change roles pane lists all assigned roles of the user with scope and resources lists. Here you can also change roles assignments.
To assign a role to an existing user/group
Do on of the following:
For custom role: set scope and resources and click the Save button, to save the changes.
For predefined role: click the Save button, to save the changes.