1. Menu –> Settings –> Applications –> Manage Applications
2. Press Menu Button –> Filter –> All
3. Find “TwLauncher” and select it
4. Click “Clear Defaults”
5. Press Home Button
6. Now you will see 2 options: TwLauncher (TouchWiz) and Home (Android Stock aka Vanilla)
7. Check “Use by default for this action”
8. Select your favorite home screen