Okay, so here are the basic ways of modding Project Diva 2nd/Extend. In particular, how I was able to accomplish Miku Miku Night Fever. I used these tools to accomplish this: UMDGen - https://umdgen.en.lo4d.com/ AFS2EXT - (this one is a pack of AFS2EXT for 2nd and extend) https://www.mediafire.com/download/2ud336ua96dh1pj Hex Editor Neo - https://www.hhdsoftware.com/hex-editor So, let's start with modding extend. The first thing I did, was to reinsert the stage of Miku 'its a spring onion not a leek' Hachune which is Miku Miku Night Fever into extend. Easy enough, right? Okay, now open AFS2EXT (for extend) and open your ISO of Project Diva Extend. Okay, now that you opened you ISO in AFS2EXT, there will be a lot of files. Now, the stages are called field_pv_xx.igb (whereas xx is the id number of the song) Luka Luka Night Fever's song ID is pv_79, and the effects are called pve_xx.igb, Therefore the the stage file of Luka Luka Night Fever will be field_pv_79.igb and the effects will be pve_79.igb. We won't be editing the effects, however. Now, hit the rewrite button, and choose the Miku Miku Night Fever stage in the folder you downloaded. Now you can close AFS2EXT and test your extend ISO in PPSSPP or something like that. It should work. Now, the music is still Luka's voice. So, that needs for more modding if you like Miku's voice to be there. This requires some more advanced modding. Now, you have to get Diva2ExSound.cpk (or Diva2Sound.cpk if you have 2nd) from the ISO, and open that in AFS2EXT (not the ISO). Now, you'll see a bunch of AIX files, which are the sound files for music and such. Just like the stage and effect files, they have the PV ID. (BGM_PV_xx) And the file you want to replace is BGM_PV_79.aix. Now press Rewrite and locate the Miku Miku Night Fever.aix file. (contained in the Miku Miku Night Fever pack) Now that you have replaced the music file, you should get this message if you successfully replaced it. Now here comes the part where you build an ISO of extend. It's not really that complicated. Open UMDGen and with that you have to open your ISO of extend. When you open your ISO, you should see something like this: Now, go to PSP_GAME > USRDIR > media > afs. There you'll see the CPK files. Now, we already replaced the stage, so no worries about replacing Diva2ExData.cpk. Now, right-click on Diva2ExSound.cpk, and press "delete". The file will be deleted, and you can go drag the new Diva2ExSound.cpk that you just modified with Miku Miku Night Fever. Part 2 below. I can't attach anymore images.