First you need to download firmware updater software from here:
Press the UPDATE and RESET buttons of OpenBench board, release RESET button wait 2 seconds and finally release UPDATE button.
Then follow these steps:
$ tar xvf ols-0308-expert.tgz $ cd ols-0308/OLS_Upgrader/ $ sudo ./ols-upgrader.sh
Unfortunately I got this error:
ols-fw-update: error while loading shared libraries: libusb-0.1.so.4: cannot open shared object file: No such file or directory Press any key to continue...
I tried to create a symbolic link to x86_64 libusb-0.1.so.4 but got this error:
ols-fw-update: error while loading shared libraries: libusb-0.1.so.4: wrong ELF class: ELFCLASS64 Press any key to continue...
Then I figured out I need to install the libusb for i386:
$ apt-get install libusb-0.1-4:i386
Finally the update worked fine.
The tip to fix the libusb I found here: http://askubuntu.com/questions/311401/libusb-0-1-so-4-shared-lib-error-in-ubuntu-64-bit-system