From the Home screen, tap Messaging .
The Messaging screen will open, where you can create a new message or open an ongoing message thread.
New Message
Tap here to create new message.
Tap an existing message thread to open it.
Tap to make a call in the message screen.
QUICK REPLY
When a New Message notification pops up, choose to reply quickly without accessing the Messaging application by tapping the Text field in the notification to respond with a text message, or tap Call to dial the contact or Delete to delete the message.