Try this
Oh dear god it worked, it worked!
Acraeus, I could pay you a beer right now.
I just unbanned myself from 002 using nothing but my own 3DS! This is incredible. And I suck at writing tutorials of any kind, so please don't count on me when it comes to that!
But basically
1. Use Decrypt 9 to extract movable.sed and LocalFriendCodeSeed_B from your current NAND that is banned
2. Open up your movable.sed with HxD and copy offsets 00000000/08 through 00000110/07
3. Open up LocalFriendCodeSeed_B with HxD and CTRL+A and then paste what you just copied
4. Save, inject to sysnand
This is how I did it, don't blame me if something goes wrong because I'm even worse at giving instructions than following them.