You can't downgrade an IOS on your iPod Touch.
You can't downgrade IOS!
No. You must restore to Downgrade the Firmware!
Yes
you dont
I have never heard any way to downgrade software.
You cannot downgrade an iPod touch with with another iPod touch's shsh blobs because the shsh blob is unique to that device. Think of it as your DNA is unique nobody can be exactly like you.
Downgrading your iPod Touch should not delete anything.
Well it's kind of IMPOSSIBLE
Downgrade your firmware to 3.1.2. This does not work for the 3G.
You cannot downgrade an iOS device without installing illegal hacks.
You first have to download a torrent of the version of firmware you want, and then you can install it onto your iPod touch