How to Jailbreak, Restore and Restore Down Idevices Running 4.0 and 4.01

JAILBREAK

1. 1
   To start off, make sure your iDevice (iTouch or iPhone) is running ios 4.0 or 4.01. If it isn't scroll down to the restoring down section to see if it is possible.
2. 2
   Go to safari on your iDevice and navigate to http://www.jailbreakme.com/ and slide the bar on the bottom that says "Slide to Jailbreak"
3. 3
   Your iDevice has officially been jailbroken and Cydia has been installed on your device rearing to go

RESTORE iDEVICE

1. 1
   Connect the iDevice to your computer via the USB connector cable.
2. 2
   Open iTunes if it has not opened automatically
3. 3
   Select the iDevice in the navigation pane on the left
4. 4
   Click the restore button and voila! Your iDevice is restoring

RESTORE iDEVICE DOWN

1. 1
   Before you restore down, you need two things: iTunes 9.2.1 or 9.2 NOT 10.0 or 10.01 (as these will not allow you to restore down) and your SHSH blobs MUST be saved on Saurik's servers, if they are not, then your out of luck
2. 2
   If you have those two things, your ready to go and lets start
3. 3
   Connect the iDevice to the computer and open up iTunes
4. 4
   Before the actual restore, you must navigate to "C:\Windows\System32\drivers\etc\hosts" on windows or "/etc/hosts" on a mac.
5. 5
   You then must add this line to the bottom of the file: "74.208.105.171 gs.apple.com"
6. 6
   save it then download the ios you want to restore to (ios 4.0 or 4.01)
7. 7
   In iTunes, when you click restore, you must hold down the shift key on windows or option key on a mac
8. 8
   Choose the .ipsw file and wait until its finished. Now you can jailbreak using jailbreakme.com
9. 9
   Finally, delete "74.208.105.171 gs.apple.com" from the hosts file