Attach your jailbroken iPhone to your computer with the iPhone data cable. Open iTunes and select your iPhone from the "Devices" option located on the left-hand side of the iTunes window. Click on the option to "Restore." iTunes will ask if you want to back up your settings prior to restoring. Select the option to "Back Up" your settings. Confirm that you want to restore your device. The restore process takes up to five minutes to complete. You will receive a confirmation when the process is complete. Restoring your iPhone will restore your phone's original settings and delete all user inputed information from your iPhone.