Updating instructions are here
http://first.wpi.edu/FRC/frcjava.html
That will take you to here:
http://first.wpi.edu/FRC/java/netbeans/update/
Make sure you download the most up-to-date files! For some odd reason, they're not in the default directory. You'll have to navigate to the 'image v20' directory, download the *.nbm files, copy them to your java computer, select tools>update or something (away from our netbeans right now, so can't be too specific), and you're done.
We had an issue where, when we tried to deploy the code to the robot, it said, ''cannot connect to OTA server''. I had to uninstall the plug-ins, and then reinstall them
Such is the life of a non-Internet connected development station...