NOTE: THIS IS FOR THE D1 AND D2 ONLY!
1. Download "Jerry's PIMMGR" or PIM Viewer.
2. Make the image you want using a image editor of some kind and using PIMMGR and save it as a .PIM. NOTE: JPEG -> PIM has some problems, I reccomend using common colors the D1 allready knows (Blue, Black, White, etc).
3. Take the NAV DVD you use and stick it in your computer.
4. Download "DVD Decrypter"
5. Open DVD Decrypter, click mode, ISO, then read.
Then click the big button at the bottom.
6. Once the iso making is done, open the image with a ISO Editor, such as UltraISO. (or for you mac users, use OSX 
)
*SKIP THIS STEP IF USING A Dual Layer DVD*
7a. Navigate to /IDX/
7b. Delete:
POIDT004.IDX, POIDT043.IDX, POISR201.IDX through POISR207.IDX
*RESUME STEPS*
8. Navigate to /BG/PIM2DIN/
9. Add the custom .PIM file you created.
10. Save the ISO
11. Burn the ISO with Nero (or equivilant)
12. Insert Burned DVD into D1.
13. Select your custom wallpaper file. The D1 will load it.
13a. DUAL LAYER ONLY: YOU'RE DONE!
REGULAR DVD:
13b. Eject the DVD and put the stock one back in.
14. YOUR DONE!
