Open the Messages app
Tap the New Message icon
Enter the names or phone numbers of the people you want to add
Type your message
Tap the Send button
To create a group text with iMessage, make sure all recipients use iMessage
To name the group, open the conversation, tap the group icons at the top, then tap Info and enter a group name
To add someone later, open the group chat, tap the group icons, tap Info, then tap Add Contact
To leave a group chat, open the conversation, tap the group icons, tap Info, then tap Leave This Conversation if available