Yes, the firmware can be updated.
The instructions are included in the README file inside the downloadable zipfile.
Can you go to that system, and as any user in Solaris, do ...
prtconf -V <enter>(uppercase "v")
Copy the short one line result back to this thread.
We'll all then be able to see what firmware level is currently on the system.
The V240's resource page in the Sun System Handbook is at:
http://sunsolve.sun.com/handbook_pub/Systems/SunFireV240/SunFireV240.html
There are download links to that platform's OBP patches, right on that page.