I think the hard part is getting your desired text into the game's font. There was a 3DS game I wanted to translate just to play personally and I had found all of the dialogue text (was just stored in text documents in a folder) but I had no idea how to put in 1 byte English characters. 1 byte English characters wouldn't show up, so if you put in characters not in the game's font odds are they won't render without being added in.