I think there will be an option in the template option part to add an image.
To give you a very easy way (it could be difficult if you're new to FTP):
You'll need to access the folders as in (/home(or whatevere here is)/wp-content/themes/eminent/images)
And upload the image you want in the "Add image" part, suppose it is "abc.jpg". Then remove image named "place.jpg". Rename "abc.jpg" to "place.jpg"
P.S. This is not at all the right way to do it. This is just a temporary method. I think you should be able to replace the image via wordpress admin.