[Jeckel]

DFU is something for complete wipes then restoring. To get into DFU (the device must be turned off!):

1. Hold down the Home and Power buttons for 10 seconds
2. Release the Power button but keep holding the Home button
3. As soon as it is detected, release the home button. The screen should be completely black.

If you hold the home button too long, you'll go into recovery mode. So should you fail the first time, just try it again but reduce the time in step 2 or step 1.