There are two steps to turn your pcDuino into an AstroBox:
1) Flashing the AstroBox system software into your pcDuino.
Follow instructions on this page.
2) Setting up your AstroBox.
At this point, you should remove your flashing SD Cards from the SD card slot and optionally insert a blank SD Card for additional file storage.
Next, setup your AstroBox following the general First Time Setup Instructions.