- Remove the SIM card from your device.
- Press and hold either the Home button—if your device has one—or the Side button, until a menu appears from the bottom of the screen.
- Tap More Wi-Fi Settings.
- Tap the Info button to the right of the Wi-Fi network that your device is connected to.
- Tap Forget this network, then tap Forget.
- Follow the steps to start using your device.
When you're finished with the steps above, insert your SIM card and rejoin your Wi-Fi network:
- Go to Settings > Wi-Fi.
- Tap the network you want to join and enter the password, if required.