From a Home screen, tap Apps (located at the bottom).
Tap Messages. If unavailable, tap the dropdown menu (located in the upper left) then tap Alphabetical. If still unavailable, refer to Manage App Icons.
Tap Compose + (plus symbol located in the upper right).
From the To: field, enter the 10-digit wireless phone number or email address. As the number is entered, a matching contact may appear and can be selected at any time. Repeat this step as necessary to add additional recipients.
Compose the message then tap Send (located in the lower right).