Use the FRC 2012 cRIO Imaging Tool.
The complete instructions are in the
Getting Started with the 2012 FRC Control System document. Configuring the cRIO begins on page 16, but you'll have to have followed the directions from the start to get all the software properly loaded first. Find it, and many other important documents, on the Kit of Parts pages on the FIRST web site:
http://www.usfirst.org/frc/kitofparts