The short version?
Install the Update Suite from the instructions here:
http://wpilib.screenstepslive.com/s/...-all-languages
Image using the instructions here:
http://wpilib.screenstepslive.com/s/...g-your-roborio
The right version? Read through each of these in order (you may be able to just skim some of them) to make sure you're not missing things:
http://wpilib.screenstepslive.com/s/4485/m/13503