Open the file put
Copy Forts & Forts.bak in the file folder and copy to scenario -
to get to scenario folder go to >Documents >My Games >Age of empires 3 >Scenario, then paste them
When in the file folder copy the mp3 file and paste it in the sound file
to get to sound folder >My coputer >local disk >program files >microsoft games >age of empires 3 >sound, then paste it