its only works on new 3ds version :p

1. Get a cia of the decomp. Universal Updater has one, but its super slow and unoptimized. I personally looked online and found one that was much better optimized. 2. You need the Data.rsdk file from a PC copy of the game.

I don't remember where you need to put the files on the sd card. So id suggest you look up a guide :/