1. Complete all Career challenges.
2. Complete all Song Challenges.
3. Complete all Guitarcade Challenges.
4. Complete the entire setlist on a single instrument in Quickplay mode.
5. Complete the entire Master Mode setlist on guitar to unlock expert drums to unlock the song.
Note: If you have already completed all Career and Song challenges, you may need to complete the entire setlist on a different instrument in Quickplay mode to unlock Metallica - For Whom the Bell Tolls.