- Download iTunes 10 for Mac / Windows
- Download iOS 4.1 for iPhone 3G / iPod touch 2G
- Download iOS 4 for iPhone 3G / iPod touch 2G
- Download Redsn0w 0.9.5 beta 5 for Mac / Windows
- Connect your iPhone to your computer.
- Turn iPhone off.
- Start iTunes
- Hold Power and Home buttons together for 10 seconds or so.
- Release Power button but keep holding the Home button until your computer recognizes a new USB device.
- iTunes will now recognize your iPhone.
Step 4: Launch Redsn0w (you downloaded above), hit "Browse" and point to the iOS 4 firmware NOT iOS 4.1.
Step 7: In this page, you have to put your iPhone in DFU mode, follow the instructions on the screen to do that.