final revised step by step...
1. i put game cart into the 6.2 3ds
2. copy gateway launcher.dat onto the sd card
3. go to
http://go.gateway-3ds.com on 3ds browser
4. select "Backup 3DS Game Cartridge"... which will dump image of the game cart to the sd card
5. Press [START] to dump Game. Wait for it to finish
6. Press [A] To Exit.
7. Turn off the 3ds and Take out the
SD Card
8. insert sdcard into my pc. There will be a .3ds file. This is the rom that was created from your retail game. Move this to your desktop. (i am now safe to give my friend his 6.2 3ds back)
9. Run gateway Rom patcher, and select load rom.
10. open the .3ds file on your desktop.
11. Click "Export header to file" and save the .bin file to your desktop
then i use No Ban No Sky to inject private header into the latest template i download from sky3ds