tutorial
1.

open the template in photoshop,
2. find a wallpaper you want to use
3. paste the wallpaper into the photoshop template

4. resize the image until it fits evenly across the template

5. move the template outline to the top layer

6. use the select tool to select the space in the middle of the template layer
7. select the wallpaper layer and press copy
8. press file>new and use clipboard preset

9. paste in the new image

10. save as 2.jpg
11. go back to the template image and press select>inverse
12. copy image again
13. paste into the smaller image you made in 8.

14. save as 1.jpg
15. move the layer left so the other part of the layer is in the frame (hold shift while moving it to make it move straight)

16. save as 3.jpg
18. upload to your phone and set your first desktop wallpaper as 1.jpg, 2nd as 2.jpg and 3rd desktop as 3.jpg
thats it
(i dont know how to resize pics for the forum)
note: i know this produces tiny little borders that are noticeable on your phone, fixing that right now