Here’s what you do, first of all you’ll need an external music player. STO is compatible with either Winamp or iTunes, personally I prefer Winamp, and you may too, especially if you use it the way I do – with Winamp for sound tracks and then keep iTunes for your iPod music.
Here are the links
Winamp | iTunes
Without further ado, here we go.
(Click the images for larger versions)

Step One
You’ll need to select a media player from in-game, this is done via the options menu under the Sound tab.

Step Two
Now you need to open the media player in-game. Log-in and in the drop down menu to the bottom right of the mini-map press “Media Player”

Step Three
Technically this could be step one, but you should really test it first before downloading the music pack. However you will need cool soundtrack music!

The URL: http://last-outpost.net/old/index.php?action=downloads;sa=view;down=50
Also, check out Dimensional Radio at: http://www.dimensionalradio.net/ then click on either the Winamp or iTunes link at the top.

Step Four
Add the music to your library and then play it, it should work while in game over the top of your games soundtrack.
It will also be a good idea to set the music to loop, you can do this by the following screen

Step Five
Play some STO with kick ass music, and do a chair dance;