Create a folder on your desktop called Pwnage
Download RedSn0w from 0.9.9b1 here and place it in the Pwnage folder.
Extract the RedSn0w zip file by double clicking it.
Launch the redsn0w application from the redsn0w folder we just extracted.
Once RedSn0w opens click the Extras button
Click the SHSH blobs button from the Extras menu.
Click the Fetch button to fetch the SHSH blobs on your device and send them to the Cydia server for storage.
Please plug your iPhone into the computer and make sure its OFF then click the Next button
RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here
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.
Your iPhone will now reboot
RedSn0w will then begin fetch the SHSH blobs from your device and submit them to Cydia.
Once this is complete you will be notified that your submission was a success. Click the Back button to return to RedSn0w.
Click the SHSH blobs button and then click the Query button to make sure Cydia has your blobs saved.
Enter * into the ECID textfield and click OK to check all your devices.
RedSn0w will now query Cydia and display the list of stored blobs.
RedSn0w also saves your blobs in a plist located within the RedSn0w folder. We would recommend keeping these for added safety.