After walking out of the bathroom you start in, you'll see a couple of soldiers conviening around a white board with tactics drawn on it.
When the soldiers run off, walk up to the whiteboard interact with it, and then make some kind of addition to it. with RT or LT, then the Bleep Bloop should be yours.
Thanks to LostNFound01
This achievement can also be gotten in the Strip Club level.
Thumbs up.
There is a whiteboard on the wall of the locked office by the dvd player.
Also don't forget to put the dvd in the dvd player for extra ego and a good laugh.
The code for the door is 4768.