You need an account with ownskin.com after this is done go to the URL
http://www.ownskin.com/create_theme?c=38
You will be greeted with an online tool
After that just click on the upload image button and upload an image from your computer you have the option of crop and rotation the image click save and the image is inserted.
After you are done with the main screen you could go to the menu page and edit the background there
You could even edit the individual icon
After you are happy with what you have created you could click to save
After saving you could download to your PC or download from the wap site at m.ownskin.com
Enjoy