Tap Camera.

If the camera is turned on:
Tap the indicator in the bottom right corner of the display and drag it right.

To change camera:
Tap the camera switch icon.

Depending on the current setting the front or the back camera is turned on.
Point the camera lens at the required object.

Tap the record icon to start the video recorder.

Tap the record icon to stop the video recorder.
The video clip is automatically saved.

Tap the photo album icon.
The video clip you've just recorded is displayed.

Tap the start or stop point on the film strip at the top of the display and drag it to the required position.

Tap Trim.

Tap Trim Original or Save as New Clip.

Tap the Home key to return to standby mode.