I tried through iTunes and the only thing available was the iTunes update itself.
Before even updating your iPhone, makesure your iTunes is updated and is at its newest version. (If you're a mac user; open itunes > press iTunes on the top bar which is next to the apple icon, then press check for updates.)
Once in a while there should be a pop-up message informing you that there is a newer version of iTunes, if you do not receive any at ALL, you probably pressed 'Do not ask again' when you saw one before. After updating your iTunes, plug in your iPod/iPhone into the computer and press the ipod name that appears at the side bar of the iTunes window, at the page where it shows your Serial Number/Code and the information of your ipod (including its' name and all that), look for the restore button, if you see that, on top of the restore button should be a button that says Update. Press the update button if the function is available and your iPod/iPhone should start updating (there will probably be some Terms & Condition window popping up, but.. come on, I mean, who reads it anyway? )
Hope this helped!