1. Go to 3ds.guide 2. Press Get started 3. Select Old 3DS 4. Select 2.1.0 Browser - Installing arm9loaderhax 5. Get to Section IV - Restoring the System 4. Input the key combo given, then select the NANDmin.bin image when prompted by pressing (A) Because I started on 2.1.0, I don't have that backup.