On the Chat List page, from the context menu of the personal chat you want to modify, click View Members.
Do one of the following:
To add a member to the chat, click Add Members. To add users from different course offerings click Select Different Course. Select the check box beside the name of users you want to add. Click Add > Done.
To add a personal contact, click Add Personal Contact. Select the check box beside the name of users you want to add. Click Add > Done.
To delete a member of the chat, on the Chat Members page, select the check box beside the users you want to remove. Click Delete > Done.