If you have decrypt9, you would do a system file dump of your movable.sed/LFCS_B from there. Use a computer with a hex editor to view the seed in comparison to your current one to see if they don't match. GodMode9 can view these files on the NAND without dumping them.
Create a NAND backup of your current settings, use JKSM to backup your saves, and then restore the old NAND to check (and pray) that there's a different seed in that NAND.
@theoldbucwild - If you have old NAND backups, find a NAND backup that has a different seed in movable.sed or LocalFriendCodeSeed_B, that's about all you can do with just one 3DS.
Do you have A9LH? Hold X and boot and restore the files you were supposed to back up. If that doesn't work, restore a NAND backup from there.
If you don't have A9LH, hopefully you were doing this on an emuNAND.
The 1 3ds method only works if the person has done a system transfer before with the NAND backup they're using. When you think of it, both methods are very similar.
I have had cherry "pizza" before basically just a pizza crust with cherry pie filling poured on it and a frosting drizzled on top. Delicious but I would hardly call it a pizza.