New OS on mac??

Hi there,

I know this problem may have already been solved but I’m a new guy so bear with me, if this is the case then well done guys and could I have the link please?

Anyway, I had previously jailbroken my apple TV and was happily running XBMC untill I installed the simplicity theme and XBMC no longer worked for me. I had already tried to uninstall XBMC but when I reinstalled and rebooted, XBMC came with simplicity and continued to crash. I figured it would be a good idea to reinstall the package with seas0npass but no use as it downloaded the new firmware and I’m way to oblivious to this forum so I (stupidly) restored via iTunes in the hopes I could start again.

Now I’m screwed as not only do I no longer have a jailbroken apple TV but I have no idea how to install the previous firmware on a mac! I’ve had a look at but the programs like iFaith seem to only work for windows. 

Please help someone, I don’t know how much more of Netflix I can stand!

Oh and the firmware on the apple TV is 5.3 I believe, hope that helps