Hi jimmy,

If you are referring to the image here(http://take.ms/tjglj), you can change it under Settings>Layout>General: http://take.ms/2ZGv9

thanks can you tell me what the size requirements are for the background image

Hey jimmy,

The minimum size is 780x400 and the suggested ratio is 4:3. But you can always try out different images to see which suits your site best.