From the main screen, press and hold the Camera button (located on the right-edge) until camcorder mode appears (approximately 3 seconds) then release. Alternatively, navigate Menu > Media Center > Picture & Video > Record Video.
Aim then press the Camera button to begin recording.
When finished, press the Camera button to discontinue recording.
Tap Video Message.
Tap Enter New, enter the 10-digit mobile number or the email address then tap Done. Alternatively, tap the Contacts icon, select (check) the contact(s) then tap Done.