ROM Hack How do I install Pokemon Art Academy DLC?

[wintercool612]

I downloaded the Pokemon Art Academy DLC from a gbatemp thread you can search for. I would link it, but this is my first post here so I'm not allowed just yet.

They come in the form of .arc files. After a lot of digging and trying many tools, I have been unable to convert them.

I have Luma installed on my 2DS. How do I go about installing this DLC?

 

[Alegria]

Make a save with checkpoint (press X to make a save of your ext data), then put your sd card in your computer, then search for "Freepaint" in that sd card. in this folder you put the arc files. After you use Checkpoint, press X again and restore the ext data
I don't know how to edit them but it would be fun

edit: strangely it doesn't work?!
edit 2: I downloaded that one (american though I'm on a european console), it works save for the mega shiny gengar