for ninjhax/ironhax sd
/3ds/spectre3ds/spectre3ds.3dsx
/3ds/spectre3ds/id1/pak0.pak
/3ds/spectre3ds/id1/pak1.pak (for registered version)

for cia or 3ds sd
/id1/pak0.pak
/id1/pak1.pak (for registered version)

create a music folder under id1 and extract this there
https://www.dropbox.com/s/7ga4lvfjnebcas8/music_082911.zip?dl=0

should look like
id1/music/02.mp3
id1/music/03.mp3
...
id1/music/11.mp3

once you get it running you will be at the console
then you can start a map using the keyboard
map start