I used the xacttool method, since that's what I'm more familiar with right now. I hope either method works for you. The command for that is: xacttool -wb "{your steam games folder/[Day or Persona 4 Golden]/snd folder/bgm.xwb file directory}" -r "NothingIsPromised.wav" -ls 860160 -le 7208960 -i 3
For the mini boss theme, replace the 3 at the end with 47.