1. BLOCK: From the home screen, select the Messages app.
   
2. Select the Menu icon, then select Blocked contacts.
   
3. Select ADD A NUMBER. Enter the desired number, then select BLOCK.
   Note: To block unknown numbers, select and hold the desired message thread then select the Block icon. Select BLOCK to confirm.
   
4. UNBLOCK: From the Blocked numbers screen, select the Delete icon next to the desired number. Select UNBLOCK to confirm.