Do some reading this is a skin not a image simply ftp the ipk to tmp then install via ipk installer on the box thers different ways to install and set as your skin for different images have a look through this thread to find out how to install and set as your skin for your image.
If your wanting to reflash a new image have a good read through the threads and post in the relevant thread or start a new one.
Just to add chabs I've seen a couple of screen shots for your next update great work on the infobar i know it's going to take a while to do so take your time.
But saying that is there any point because when sky change a channel name it won't display the png for that channel or does it revert back to the default preview.png when there's no png for that channel?