How to Downgrade iPad to From iOS 6 to iOS 5 and 5.1.1 (Mac)
how to downgrade your iPad 2 from iOS 6.x to iOS 5.x using saved SHSH blobs and Redsn0w for Mac.

You will need to have saved SHSH Blobs for iOS 5.x and iOS 4.x for this tutorial to work.

Step 1:
Create a folder on your desktop called Pwnage

Download the latest version of RedSn0w and place it in the Pwnage folder. Likewise, download the 5.x firmware you would like to restore to and the 4.x firmware you have saved SHSH Blobs for and place it/them in the Pwnage folder.

Extract the RedSn0w zip file by double clicking it.

Step 2:
Right click or control-click the redsn0w application from the redsn0w folder we extracted earlier and choose Open from the popup menu that appears

Step 3:
Click Extras from the main menu.

Step 4:
Click Even More from the Extras menu.

Step 5:
Click Restore from the Even More menu.

Step 6:
Click IPSW from the Restore menu, choose the IPSW you would like to restore to from the window that appears, and click Open.

Step 7:
When prompted, connect your iPad 2 to the computer in normal mode and click OK

Step 8:
You will be informed that a 4.x IPSW will be required to continue. Click the OK button.

Step 9:
Select the 4.x firmware IPSW from the Pwnage folder on your desktop and click Open.

Step 10:
Your iPad will now be placed into recovery mode.

Step 11:
RedSn0w will check Cydia to see if you have the correct blobs saved.

If RedSn0w is unable to find your blobs automatically click the Remote button to try again or you can click the Local button to search for blobs on your computer.

Step 12:
RedSn0w will prepare the 4.x restore image.

Step 13:
You will then be prompted to place your iPad into DFU mode.

Step 14:
Connect your device, turn it off, and then click the Next button

Step 15:
RedSn0w will now guide you through the steps to get into DFU mode.

Hold down both the Home button and the Power button for 10 seconds.

Release the Power button and continue holding the Home button until RedSn0w detects the device.

Step 16:
Your iPhone will now be exploited with limera1n.

Step 17:
RedSn0w will now restore to iOS 4.x.

Step 18:
Once the restore to iOS 4.x is complete, RedSn0w will put your device back into recovery mode and prepare the iOS 5.x restore image.

Step 19:
iOS 5.x will now be restored.

Step 20:
You'll be notified once the restore is complete.