you can not, because it is not in DFU mode.

Put the iPod into DFU mode, then you get to format the iPhone in iTunes.

""Put the device into DFU mode.""

DFU MODE STEPS

Hold the Power Button (3 secs)

Continue holding the power button and also hold the home button (15 secs)

Release the power button while continuing to hold the home button (10 secs)

Your device should prompt with the "Connect to iTunes Screen"

Second: Plug it into your computer and open iTunes. It will either prompt to restore and up date or you can manually restore using the following steps.

Now follow the steps in iTunes

https://support.apple.com/en-us/HT201252