I have something i'd like to request... Where should I post my request?

What music codes can I use to get music in Hanebow? (EX: T01, B03, etc.) Is it even possible to change the music?

I tried looking  for a while but I found nothing, so can anybody explain to me or at least give me a link to a tutorial on how to create a .rel file?

Okay so I opened up Common3.pac in BrawlBox. After I changed a bunch of item textures and stuff I saved it and put it in my SD card in the directory: pf/system.  But  in game the items aren't showing up, what am I doing wrong??