People Options
There are several People Options available in this Group Conversation. By default, there is a check mark to Show the Participant List.

The Invitations are:
Invite by Name or Phone Number
Invite by Email

The Presentation options are:
Mute Audience
Make Everyone an Attendee
Play Entry and Exit Announcements
Remove Everyone and End Meeting

6. Try It: End the Meeting
Go to People Options.
Click on Remove Everyone and End Meeting.

The Attendees will be notified that the meetings has ended. (The donuts were all gone, any way.)

Please Close the Group Conversation.

Clair's Lync->Group Conversation->People Options->Remove Everyone and End Meeting