Delete one number from a group?

Greetings, artysan.

It appears that you've added a contact with incorrect information in a group text message. You'd like to remove the one from the group, and we're glad to help with this.

Add and remove people in group text messages - Apple Support -- It depends on what type of group message it is:

"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. But you can’t add or remove people from group MMS messages or group SMS messages."

If it's an MMS or SMS message, you can't remove a person. However, you can start the conversation again excluding the one you no longer want to include.

Take care.

You're welcome Peter. We're glad we could help.

Have an excellent day!