Step By Step Instructions to Downgrade a 3GS From 3.1 to 3.0 (Mac and Windows)

Discussion in 'Jailbreaks and iOS Hacks' started by tctony, Oct 9, 2009.

  1. tctony macrumors 6502a


    Jun 15, 2009
    1.) This will only work if you used the "Make My Life Easier" button within Cydia to store your ECIDs.

    Mac Instructions

    2.) Download BBEdit from

    3.) Once installed, open BBEdit, go to "File" then "Open Hidden." Go to Mac HD > Private > etc > hosts and open the hosts file. You will need to go to the dropdown box and select "open all types of files" to select it.

    4.) Once you have the hosts file opened, go to the very bottom of the file, and paste "" at the bottom. Go to file > Save.

    5.) Put your phone into DFU mode. (With phone plugged in, hold home button and sleep button for ten seconds, then release the sleep button while keeping the home button pushed down, until an iTunes prompt pops up.)

    6.) Option + click the Restore button, and point it to iPhone 3.0 OS, and Open. You can download the OS from here.

    7.) After the restore process is finished, you can use redsnow 0.8 to jailbreak.

    Windows Instructions

    2.) Open Notepad with Administrative privileges (Right click on Notepad, open as administrator.

    3.) Open the hosts file from C:/ > Windows > System32 > Drivers > etc.

    4.) Add "" to the bottom of the file, and save.

    5.) Connect your phone, and put it into DFU mode (see instructions above).

    6.) I believe it is shift + click to update (correct me if wrong), then point it to the 3.0 ipsw.

    7.) Jailbreak with redsnow .8 (if that works on Windows...I don't have Windows, so I don't know.)

    Everything should work.
  2. CactusHawk macrumors regular

    Oct 9, 2009
    I get to step 6 where I option click FW 3.o and iTunes gives me an error saying the FW is compatible:confused:

    What am I doing wrong?

    EDIT: Nevermind. I was using an old FW (for 3g not 3gs)
  3. tctony thread starter macrumors 6502a


    Jun 15, 2009
    I assume everything worked out after you got that fixed.

    I also added a link in the first post to download prior iPhone OS'.
  4. TSX macrumors 68030


    Oct 1, 2008
    Does this work for 3.1 out the box?

  5. CactusHawk macrumors regular

    Oct 9, 2009

    Worked perfectly. Thanks for the easy to understand directions. I actually used these instructions to restore a 3GS that was JB on 3.0. I was having a memory leak and just needed to restore.


Share This Page