Drag the 3ds folder in the zip below to the root of your SD card (replace common files if any)
I just threw the .3dsx JK pointed you to, and the xml to go with it into a folder. Felt like it would be a tad easier than saying "wrong file, go here to download the right ones and put them here and there and" Blah
This will add an app to the homebrew launcher, called something like JKSM or JK's save manager. Regardless, that's the app you want