How to unlink nands:
1. In sysnand, go to System Settings -> Other Settings -> Format System (Do not accept yet)
2. Eject your Sd card (don't worry, it is safe)
3. Accept to Format your 3DS/2DS (let it connect to the internet if it asks, it will not update your system)
4. After it reboots, go through the setup screen and set everything up
5. Once in the home menu, insert back your sd card and let it create some files on your sd card.
6. Your nands are now unlinked, and there are 2 ID folders in your Nintendo 3DS folder on your SD card (one for emunand, another for sysnand)
How it will look on your SD card:
The folder with the smallest size belongs to your sysnand, since you just formatted it. Grab the
database zip again and put the title.db and import.db in YourSysnandFolder/RandomNumbersAndLettersFolder/dbs, just like you did in Part 1: Line 1 & 2! Don't forget to go to Data Management in Sysnand to let the 3DS "repair" your software management information!