How To Downgrade Your iPhone From iOS 4.0.2 To iOS 4.0.1/iOS 4 Without SHSH Blobs [Mac]

Step 1:

Download iPhone Firmware Version (iOS 4.0.2 & iOS 4.0.1/ iOS 4.0)

Step 2:

Rename the downloaded file extension from .ipsw to .zip

Step 3:

Now, extract the .zip file that you have just changed.

Step 4:

Open the Buildmanifest.plist with TextEdit

Step 5:

Now, Click “Command” + “F” to get the Find & Replace Windows.

Step 6:

Here, In the pop up window Type “8A306? (if you are using iOS 4.0.1)/ “8A293? (if you are using iOS 4.0) in Find Field & “8A400? in Replace field

Step 7:

Click on “Replace All” and Save the File

Step 8:

Now, Open the Restore.plist with Text Edit

Step 9:

Now, Click “Command” + “F” to get the Find & Replace Windows.

Step 10:

Here, In the pop up windows Type “8A306? (if you are using iOS 4.0.1)/ “8A293? (if you are using iOS 4.0) in Find Field & “8A400? in Replace field

Step 11:

Click on “Replace All” and Save the File

Step 12:

Now, take the iOS 4.0.2 firmware file, rename its extension from .ipsw to .zip

Step 13:

Extract the iOS 4.0.2 file that we have just rename its extension and leave it open.

Step 14:

Now, move all the iOS 4.0.1 / iOS 4.0 files to iOS 4.0.2 windows (Folder that we have open in Step 13)

Step 15:

Once moved, Delete all the dmg files that have 002 at the end, leaving only the 001 files left and Close this windows.

Step 16:

Now, Change the iOS 4.0.2 firmware extension to .ipsw from .zip

Step 17:

Click on Finder and while holding SHIFT + COMMAND Key press “G”.

Step 18:

In the field type /etc/ and Hit enter.

Step 19:

Now, look for the file name hosts and open it with TextEdit.app

Step 20:

Now, add the following line at the bottom of the file (if you have 127.0.0.1 gs.apple.com in the file comment it out by adding # in front of the line)

74.208.10.249 gs.apple.com

Step 21:

Step 23: