once downloaded, how do i install this theme on my wp .org site? i have no idea which version i have, i checked an arbitrary number since it would not let me post the question without putting something in.

The help manual for this theme says As you can notice from the demo in the top of each page & post there is an image. To replace the
default image, please replace ‘bgimage.jpg’ located in the ‘images’ folder of the theme with your own.
I want to use a different image but cannot locate the images folder or the bgimage.jpg photo.