Hi Simone,
You have several firmware files within the Cockpit directory (browse to the specific installation folder in your system).
There is a folder called "firmware". I guess you can find your particular file based on your specific tool.
Once you know where is your file, you can flash it into your device using LPCXpresso and JTAG connector.
I followed these steps and I could use the Cockpit GUI again as before.
Good luck!
Roberto