Let me give you an example with the first song "I'm Back" ~ ~ Open the Zhu Xian folder, then open the element folder and find the one inside.

Music folder. There is a theme_a.mp3 in the music, which means "I'm back" at the beginning. You name the music to be replaced as theme_a.mp3, and then paste it in to replace the original file. Then you try to drive Zhu Xian, and the replacement should be successful. Replace one by one according to this method ~

I don't know how to change them at once. Now it seems that we can only change them one by one.