We covered iLex RAT in previous, which can restore your idevice clean but without losing jailbreak. Now the developer just released a major update to the super tueak, and it got an even super feature: resotre your idevice to 'stock' - that means the status of 'unactivated.'
Video via IDB
How to use iLEX RAT to restore your jailbroken device back to 'stock'
1) Lauch "Cydia"
2) Go to "Manage" and "Sources", Click "Edit" and "Add" new repo:
cydia.myrepospace.com/iLEXiNFO/
3) Back to Cydia Sources.
4) Select "iLex R.A.T" and "Install"
5) iLex R.A.T installed.
6) Go to "Cydia" -> "Search"--> type "MobileTerminal"
7) Install "MobileTerminal". Done.
8) Lauch "MobileTerminal"
9) Type: rat + Enter
10) It will come up a menu, with 13 choice. Type: 12 + Enter.
11) Then an warning will come up. Press 'y' to continue. And wait.......
12) Type 'y' to reboot your device.
13) In the process you will see the expected view: Isn't it looks familiar!!!
14) You have new iPhone with totaly clean Jailbreak. Never ask where is iLex RAT, it is an invisible hero!
