Procedure

1. Go to Menu
2. Go to User Buttons
3. Under Action Column Touch-Recording
4. Under Selection Column-Touch Do for All Tracks
5. Under Detail Column Touch Toggle Mic/Track
6. Assign User Button to any User Button 1-8
7. Touch Assign Button
8. Are you sure screen will pop up, Touch Assign to store in that User Button
9. Touch Rec/Play Tab
10. Touch Record Mode Tab
11. External Recording & Playback Mode Screen Pops up
12. Touch Multitrack USB Drive or Multitrack DAW
13. When you Touch the Toggle All Track User Button all Tracks will be available for Playback, there is no need to do them one by one.