Tap the message icon.

Tap the required sender.

Tap the required MMS to read it.
Slide your finger upwards starting at the bottom of the display.

Tap the return icon.

You have a number of options when you've read the MMS:
Reply to MMS, go to 2a.
Forward MMS, go to 2b.
Delete MMS, go to 2c.

Tap type a message.

Write the text for your reply and tap the send icon.

Tap and hold the required MMS until a pop-up menu is displayed.

Tap forward.
Key in the first letters of the required contact.
Matching contacts are displayed.

Tap the required contact.

Tap the send icon.

Tap and hold the required MMS until a pop-up menu is displayed.

Tap delete.

Tap delete to confirm.

Tap the home icon to return to the home screen.