Find "Messages"
Press Messages.
Read iMessage
Press the required sender.
Select option
You have a number of options when you've read the message:
Reply to iMessage, go to 3a.
Forward iMessage, go to 3b.
Delete iMessage, go to 3c.
Reply to iMessage, go to 3a.
Forward iMessage, go to 3b.
Delete iMessage, go to 3c.

3a - Reply to iMessage
Press iMessage.
Write the required text and press Send.
3b - Forward iMessage
Press and hold the required iMessage until a pop-up menu is displayed.
Press More....
Press the forward icon.
Key in the first letters of the required contact.
Matching contacts are displayed.
Key in the first letters of the required contact.
Matching contacts are displayed.
Press the required contact.
Press Send.
3c - Delete iMessage
Press and hold the required iMessage until a pop-up menu is displayed.
Press More....
Press the delete icon.
Press Delete Message.
Return to the home screen
Press the Home key to return to the home screen.