This article is for transferring data between systems without doing a system transfer, and usually should only be done if the console you are transferring from is nonfunctional.
If you do not have a specific reason to follow this guide (i.e. both consoles are usable), do a System Transfer instead.
This guide can potentially cause unexpected results if done wrong. Please ensure you read the steps carefully to prevent these unexpected results from happening.
Additionally, ensure you have read the following warnings to have a full understanding of the potential risks of this guide.
Do NOT use a movable.sed from Bruteforce Movable (in general, but especially not for this guide). Doing so may cause other issues with the system, and will result in a guaranteed brick if you uninstall CFW while using that movable. Always keep a backup of your original movable.sed if you do so.
Uninstalling CFW without undoing the moveover done in this guide WILL brick your console, as we have tampered with console-unique files which can have dangerous effects if stock (native.firm) is booted.
This guide has you extract the original versions of those files so you are able to undo it if you need to - do not lose those files.
Any games/savedata/themes/DSiWare that was already on the destination console's SD card will become inaccessible once the guide is completed - only data transferred over from the source console will be usable. To access the destination console's data again, you must undo the moveover.
If the above two warnings will cause issues for you and you are willing to take extra steps to avoid them, you can instead use ninfs to merge the source console's encrypted files onto the destination console, then rebuild title.db to make any merged games/apps appear.
However, note that even this method will not bypass the issues of using a Bruteforce Movable movable.sed.
The latest version of GodMode9 (the GodMode9 .zip file)
Prep Work
Follow this section on the destination console only.
Power off your console
Insert your SD card into your computer
Copy GodMode9.firm from the GodMode9 .zip to the /luma/payloads/ folder on your SD card
Copy the gm9 folder from the GodMode9 .zip to the root of your SD card
Create a folder named 3ds on the root of your SD card if it does not already exist
This folder stores homebrew applications and data; it is different from the Nintendo 3DS folder that the console automatically generates
Copy faketik.3dsx to the 3ds folder on the root of your SD card
Copy the source console'sessential.exefs to the root of your SD card and rename it to old-essential.exefs
If you have the source console'smovable.sed already, you can copy that to the root of the SD card instead
Reinsert your SD card into your console
Backing up the destination console's essential.exefs
If you do not back up the destination console's essential.exefs before following the remainder of the guide, you will be unable to undo the moveover - which means that console will never be able to uninstall custom firmware.
Press and hold START, and while holding START, power on your console. This will launch GodMode9
Enter the [S:] SYSNAND VIRTUAL drive
Press A on essential.exefs to select it
Press A on Copy to 0:/gm9/out
If you see Destination already exists, press A on Overwrite file(s)
Press A to continue
Press B until you return to the drive list
The destination console's original essential.exefs file will be in /gm9/out folder on its SD card. It is highly recommended to back up this file to a safe location.
Extracting the movable file
Enter the [0:] SDCARD drive
Select the old-essential.exefs, and press A on Mount as EXEFS image
If you instead copied movable.sed to the SD root, press Y on that file and skip to the next section
Look for a file named movable inside the old-essential.exefs image mount
Press Y on movable, then proceed to the next section
Replacing the movable.sed
Press B to return to the drive list
Enter the [1:] SYSNAND CTRNAND drive, then enter the private folder
Press X on the movable.sed file and press A
Unlock Writing to SysNAND (lvl1) when prompted, then input the given key combo
Press Y to paste from the clipboard, then rename the file to movable.sed if it is not named that already
Press B until you have returned to the drive list, press R + A on the [1:] SYSNAND CTRNAND drive, and then select Fix CMACs for drive
Once this finishes, press START to reboot your console
Your console will act like it has just been formatted - this is supposed to happen. Proceed through initial setup and get to the HOME Menu
Getting your apps back
Launch the Download Play application
Wait until you see the two buttons
Do not press either of the buttons
Press L + D-PAD DOWN + SELECT at the same time to open the Rosalina menu
Select Miscellaneous options
Select Switch the hb. title to the current app.
Press B to continue
Press B to return to the Rosalina main menu
Press B to exit the Rosalina menu
Press HOME, then close Download Play
Relaunch the Download Play application
Your console should load the Homebrew Launcher
Launch faketik from the list of homebrew
Wait until the process is completed
Press START to exit
Reboot your console
The moveover is complete. Congratulations for performing a complex procedure.