How to Unlock the Galaxy S8/S8+ device if it is Locked by Face Recognition?

When using Face Recognition to unlock your device, your phone could be unlocked by someone or something that looks like your image. As Face recognition is less secure than Pattern, Pin, or Password, we recommend using the Iris recognition, Fingerprint recognition, Pattern, Pin, or Password to lock the device. Additionally, if you use your face as a screen lock method, your face cannot be used to unlock the screen when turning on the device.

To use the device, you must unlock the screen using a pattern, PIN, or password you set when registering the face.