Just the two songs in Left 4 Dead 2’s main directory\left4dead2\sound\music\flu\concert.

What the poster wants to do is to copy these two songs. , put it in another folder for backup to avoid future restoration.

After the backup, the author will delete the two songs in the directory just now, put the music he wants to change into it, and finally put the music Rename it to the name of the original music (just copy it from the backup file)

Finally, I wish you a happy game~