You can't system transfer from N3DS to O3DS (and even if you could you can't transfer pirated games through it), so you just have to reinstall everything as the only other alternative is making the O3DS's NAND the same as the N3DS's, which brings a TON of potential issues or even brick with it. Dump all installed titles and backup all saves/extra data (JKSV has mass dump option for those), then install the CIAs on the O3DS and restore the saves/extra data. No other safe way, but I get it, it takes a lot of time, not just installing but dumping as well, although mass dump for titles exists as long as you got space on the SD card.