First, hover over “pages”, and select “all pages”.
This will bring up the pages area. Select the page you wish to add the Header Image to.
Next, navigate to the “Header Image” area, you can then select “Add Image”
This opens up the media library area. You can then navigate to find your image (if it is already stored in the media library), or add a new one.
Once you have located or selected your image you wish to use click “Select”.
You will then need to crop the photo. When you are happy with your selection click “Crop”
You will then see a small preview of the image selected on your page. You can then click “preview changes” to preview the page, and then you must go back and click “update”. This will save the changes made.