I had a bit of effort to get this to work, so I’ll share my findings.
I installed FireCore atvflash on my original silver Apple TV. But couldn’t get Nito Smart Installer to work. I kept getting an error message to the effect that “mhelper has the wrong permissions or owners to work properly”.
I tried the recommended solution, but no help. After some messing around and googling, my solution was to do an installation of Nito TV through SSH, as explained here.
Basically, it’s beyond easy.
Open SSH (I use Putty).
ssh -1 frontrow@AppleTV.local
cd “nitoTV Take Three”
chmod 755 installme
Reboot the box. Just type “sudo reboot” from your SSH session.
[If you have trouble getting to your Apple TV box (which should be accessible as AppleTV.local), just use the IP address of the Apple TV box directly. You can get the IP address by checking your wifi router. The user name and pwd for the box is always “frontrow”]
Then, go into the Nito TV menu, install Smart Install. It may fail once. Just try it again. It should work fine.