remove a contact from group message

You must be in a group iMessage to add or remove people.

"Add or remove someone from a group conversation

Anyone in a group iMessage can add or remove someone from the conversation. You can remove a person from a group iMessage that has at least three other people. You can’t add or remove people from group MMS messages or group SMS messages.

Add a person

1. Tap the group conversation that you want to add someone to.
2. Tap the top of the group conversation.
3. Tap , then tap Add Contact.
4. Enter the contact information for the person you want to add. Then tap Done.

Remove a person

1. Tap the group conversation that has the contact you want to remove.
2. Tap the top of the group conversation.
3. Tap , then swipe left over the name of the person you want to remove.
4. Tap Remove, then tap Done."

https://support.apple.com/en-us/HT202724#types

-AJ