How can I replace the audio?

To change the audio of a track, enter your account, select the album, enter the track you want to change, delete the existing audio and upload the new audio again.

1. Open the disc and go to "3. Tracks": 
   
   
2. Select the pencil to enter to edit the desired track: 
   
3. Select "Erase Audio":
   
4. Once deleted, select "Upload Audio" and upload the desired audio from the computer:
   
   
5. While the new audio is being uploaded, the following message will appear. You can continue editing the album normally, as this process may take a few minutes. Captura_de_pantalla_2019-06-20_a_las_17.55.02.png
   
6. You can check that the audio is loaded when you see the option to play next to the track title:
   

When you're done, perform an update so that the change reaches the selected channels.

If the song has already been distributed, should I unsubscribe and upload it again?

It should NOT be redistributed. First, you must replace the audio and then perform an update so that the new audio reaches all channels.