You can't change the people in an existing chat. But, you can start a new message and add or remove people from the previous chat.
You can add or remove people to create a new conversation with a different group of people.
- Go to Google Chat or your Gmail Account.
- In Chat, at the top, next to the conversation name, click the Down arrow Start a new chat.
- In Gmail, click More options Start a new chat.
- Add or remove people from the existing group conversation:
- To add people, enter their names.
- To remove people, next to their name, click Remove from room .
- Click Create.