Find "Display"
Press the Navigation key.
Scroll to Settings and press the Navigation key.
Scroll to Device settings and press the Navigation key.
Scroll to Display and press the Navigation key.
Select background image
Scroll to Wallpaper and press the Navigation key.
Go to the required folder.
Go to the required folder.
Highlight the required background image and press the Navigation key.
Press the Navigation key to select the background image.
Exit
Press Disconnect to return to standby mode.