1. From the home screen, tap the Messaging icon.
   
2. Touch and hold the Desired message thread.
   
3. Tap Add to block list.
   
4. Tap OK.
   
5. To unblock a contact, tap the Menu icon.
   
6. Tap Blocked messages.
   
7. Tap the Block list icon.
   
8. Touch and hold the Desired blocked number or contact.
   
9. Tap Remove from blocked list.
   
10. Tap OK.