In order to hard reset a Samsung Google Nexus S I9023, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Samsung Google Nexus S I9023 device will be brought back to the default configuration of a brand new device.
1. Turn off the phone.
2. Press & hold the Power + Volume Up buttons. Keep holding them until the boot mode menu opens.
3. Using Volume Up and Power buttons, select Recovery.
4. Android screen with an open chest will appear on-screen. When it does, press the Volume Up and Power buttons at the same time.
5. Continue by selecting Wipe Data/Factory Reset.
6. Next select Yes - delete all user data and Reboot system now.
7. Done.