To change the background image for the row in the LiveEditor there are two simple steps:
1. Click the row edit icon at the top of the area you want to change the background for – this looks like a pencil:
2. Scroll down in the row options window and find the “Row background image” section and click the “Select File” button to choose the image you want to upload:
Below the image you can also set the type of tiling you want – if you are using a large single image you would normally want to use the Cover/Stretch option
If you need to change the page background image –
see this tutorial