1. Open your phone's Settings app.
2. Find the Wireless & Networks heading at the top of your Settings menu.
Depending on your device model and current software, you might have to tap a Connections tab at the top of your screen.
3. Tap Wi-Fi under Wireless & Networks.
4. Slide the Wi-Fi switch in the upper right corner of your screen to On position. You will now see a list of all available Wi-Fi networks around you.
5. Tap and hold the network you want to forget. It will open a window with network options. Tap Forget network.
Depending on your device and software, you might need to tap on the network instead of tapping and holding.