- Plug your iPad into your PC/Mac and open up iTunes
- Shift-click (Windows) or Option-click (Mac) the “Restore” button in your iTunes iPad device summary page. Find the firmware that you’ve downloaded, and restore.
- After this is complete, iTunes will ask you if you want to set up your iPad as a "New" device, or from a previously stored backup. If your goal is to return to a life before jailbreak, you’re probably going to want to restore.
If you forgot to back-up your device (DOH!), you may end up with iOS 3.2.2 on your iPad and will be stuck without a Jailbreak until at least November since the Dev Team appears to be waiting for iOS 4 to jailbreak.