Any possible way of swapping music?

[MarbleD410]

Hello, I was just asking about is there a way I can swap The game's music with the classic music, I only wish to play single player with the classic music instead of the original.
When I extracted one of the files

Like: SND_MUS_Armory.xxx

I can't seem to return it back to the same file after turning it into a folder.

Help would be nice.