I'll teach ya its simple, problem is, I can teach you how to play a song in lua, but not change a clique theme song.
1.First of all you need to crack the audio files
2. Then write this at your lua script :
SoundPlayStream("", 0.69999998807907)
Inside the "" put the songs name, that you cracked from the music bin.
Here is an example of a name of a song from the music bin : MS_FightingBullies
As the name suggest, it is the theme song for the bullies.
Anyway, If you have any questions on how to crack the audio or anything else, dont be afraid to ask.