My instructions will only work for you if you have the save file with the proper payload for your console firmware version, seeing your from Vietnam, unless you are in possession of a N/O3DS save file for 10.3(E <---- I think this would be yours, not totally sure my world Geography isn't all that great from memory) my instructions for you will only be good after that point. Maybe someone else has the other firmware payloaded save files that they can upload for you to use, unfortunately I only have the saves for N/O3DS's for american consoles.