1. You will need to find an image of an AppleTV 1.0 drive somewhere on the internet. I will not tell you where as it is copyrighted material.
2. Create a recovery.dmg from your current AppleTV (regardless of what firmware its on) by ssh'ing to your AppleTV and type: sudo dd if=/dev/disk0s2 of=recovery.dmg bs=1m
3. This will create "recovery.dmg" at /Users/frontrow/
4. Copy this to your Mac and mount it. Inside you will see OS.dmg. Delete the recovery.dmg from your AppleTV.
5. Mount the image of AppleTV 1.0 on your Mac. You should see inside another OS.dmg
6. Replace the OS.dmg inside the recovery.dmg you just created with the one from the AppleTV 1.0 image.
7. Copy recovery.dmg back to your AppleTV in /Users/frontrow/Documents
8. Copy 10.4.9 Combo update to /Users/frontrow/Documents
9. Run NitoTV smart installer.