How to install iPhone Software on iPod touch (1st generation) with an IPSW file
Back up your iPod touch (1st generation) first. Connect it to a computer, open Finder on macOS or iTunes on Windows, then hold Option (Mac) or Shift (Windows) while you click Restore and pick the IPSW file. Your device will be erased and the selected version installed. Follow our restore guide for every step.
Only firmware marked as Signed can be installed today. To leave a beta and return to the public release, restore the latest signed release build listed above.
