Hacks Cannot uninstall early unicode font hack file for K21 in OS 2.52

[yuenslhk]

Hi , I am a Hong Kong People and use Kindle 2i with unicode font hack(early version) , after the kindle OS update to 2.5.2 , I find that I can jailbreak the kindle 2 international with a jailbreak file , and still continue to install the old version unicode font hack, but now I found that I cannot update automatically and wirelessly though amazon server ( to 2.53) , and besides , I cannot uninstall the unicode font hack ( even using the new uninstaller provide by blogkindle), can someone provide a way for me to refresh the kindle firmware in order to uninstall all the old hack file from kindle and then let me to upgrade to the new kindle 2.5.3 OS and install the new unicode hack which will work in 2.53?

Moreover , the new unicode font hack is ready , I hope to install this hack but now I can't uninstall the old hack file , before install the new version, can someone provide a way for us to really hard reset the kindle 2 international and make it really become the factory default?