Here is a detailed article with all the steps and code you need here to reset the restrictions passcode on iPhone – http://bit.ly/forgotRestrictionsPasscode
No jailbreak is needed – just a free download.
Below are the primary steps but please see the link above for detailed steps:
1. Backup iPhone (don’t encrypt backup).
2. Download and open “iBackupBot” – http://www.icopybot.com/itunes-backup…
3. Navigate to “System Files” -> “HomeDomain” -> “Library”.
3. Find and open the file com.apple.springboard.plist.
4. Find the string ‘countryCode’.
5. Copy and paste specified string ( see http://bit.ly/forgotRestrictionsPasscode).
6. Save the “plist”
7. Restore your phone from the backup that you just edited.
8. Navigate to Restrictions, enter the pin, and then you should be in!