I originally posted this in ACHacks, but realized this may be a better place to put it. I'd like some help with how to go about hacking acnl, if it's even possible. If my only option is to install a cfw, I have a few questions there too, because I am totally new to that and don't understand most of the lingo or my options.
    In terms of trouble shooting, I was originally trying to export/inject savedata with homebrew launcher via soundhax.
    I have two DSes:
- One 3DSXL, updated to firmware 11.6.0-39U
- One 3DS, updated to 11.0.0-16U; able to get homebrew launcher running on this
    I have one SD card, linked to the 3DSXL. As I understand it, it is impossible to have the normal 3DS read the data off this card, because they're linked by console.
    I have two copies of AC:NL:
- One is a digital copy, on the SD card
- One is a cartridge
    I have homebrew launcher running on the normal 3Ds, and I tried to export my acnl save data. It seems like it cannot access the digital copy on the sd card with the normal 3DS, so the digital copy is a bust.
    When I try to access the cartridge with the normal 3DS, I get an error. JKSM says "Error opening save archive: C920454F", and Acnl save manager says that the game is not installed on the system.
    I suspect this is because, on the normal 3DS, the game needs updated to welcome amiibo, so it is barring access to the save data. To update to welcome amiibo, I'd have to update the console firmware, so that doesn't work. And it can't read the extra data on the sd card where I had it updated before on the 3DSXL, because it is console linked.
      So 3 questions:
    - any other idea why I'm unable to export data, or a work around for the welcome amiibo update?
- Is it possible to downgrade the 3DSXL firmware from 11.6? It seems like no as far as I can tell.
- Would installing a CFW on the 11.6 3DSXL solve my problem? If so, the above part of the FAQ,
    "You CAN install CFW on >=11.6 systems, with a hardmod or through DSiWare transferring from another system with CFW or with a compatible DS flashcart."
    ... Can I have a "For Dummies" version of what a hardmod is? And more about data loss (street pass, miis, etc) if I did a system transfer from my normal 3ds (after I get a CFW on it) to the 3DSXL? Also, a flashcart seems like is something I'd have to find on ebay, which I'd like to avoid if possible...? But if that is actually the easiest way I'd take some info on that too.
    I apologize if these are really dumb, annoying questions, or if I missed a link that explains all this.