Enter DFU Mode
Use this function to put the device into DFU mode.

DFU stands for 'Device Firmware Update' and is a special kind of recovery mode.
DFU mode will cause iTunes (when launched or open) to ask you to restore the device.
You can exit this mode only by restoring the device in iTunes.

How to enter DFU Mode manually:
hold down both the 'Sleep/Wake' and 'Home' buttons until the screen goes black (about 10 seconds,) then let go of 'Sleep/Wake' and keep holding the 'Home' button until iFuntastic shows the status as 'DFU Mode' (or iTunes, if running, detects the device.)

Entering this mode is tricky and may take several tries.