It supposedly can be changed using the HXF Tool; however, I haven't been successful using it yet. I'm working on trying to get some help on this similar question on this thread:

http://www.dingoo-digital.com/forums/general-talk/using-hxf-tool-modify-firmware

In addition, I came across this (start at around post #7):

http://dingoo-digital.com/forums/firmware-hacking/easier-way-upgrade-firmware

This is where I'm at so far. Hope this helps a little.