Open the group chat in the Messages app. Type the new group name. Make sure you follow group texting etiquette rules, especially if you use the chat for work! Enter the new name, then choose a emoji, ...

Open the Google Messages app, tap the Start Chat button, and select Create Group. Select the contacts that you want to add to the messaging group. Then, tap the Next option.

Hit the chat icon in the top-right corner of the main page. Tap any conversation in your inbox — it doesn't have to be a group message. Tap the individual or group chat name at the top of the page.