In order to manage user roles, just open User Roles page by selecting it from sidebar navigation menu.
Create New Role
To add new role, simply enter new role name and click Add. New role will be automatically added. It's recommended to use one word role because it will be easier for you to check if user has specific role inside the source code. Every role name will be converted to lower case.
To delete role, just click Delete button next to role you want to delete. If there are users that already have this user role, they will be returned back to User role.