Originally Posted by DrMoze
Newer update: I actually managed to install Cyrillic text in my 500. I will post instructions later (based on what I did and what I figured out from a google-translated webpage from the the-ebook.org site). Hopefully to help others avoid my brick experience.
BTW, I did the basic upgrade, and was then able to do a regular reflash with hackbuilder to get the hacks installed (joystick page turn,clock, direct page access, new icons, small menu fonts) together with Cyrillic support.
Congrats! Without speaking Russian, you've done a great job.