You can change a user’s role and group from the Members tab at any time. Just click the dropdown menu under Role or Group by their name, and select their new classification.
If you need to change the role or group for multiple users at one time, click the checkbox icon in the top right corner of the Members page. Select the users you need to modify by toggling the checkbox by their name. Then click the Manage button, choose their new role and group from the dropdown menus and click Confirm to save.