Add or remove someone from a group iMessage conversation. Anyone in the group message can add or remove someone from the conversation. To add a person to a group message, tap Details, then tap Add Contact. You can remove a person from a group message that has at least four people.Tap Details, then swipe from right to left on the name of the person you want to remove.Then tap Delete.o add a person to a group message, tap Details, then tap Add Contact. You can remove a person from a group message that has at least four people. Tap Details, then swipe from right to left on the name of the person you want to remove.