To reset the radio in a 2018 Silverado, press and hold the "Home" button on the radio screen for approximately 10 seconds; this should initiate a reset of the infotainment system, including the radio settings.
Key points to remember:
Locate the "Home" button: This is usually a prominent button on the radio screen.
Hold the button: Press and hold the "Home" button firmly for at least 10 seconds.
Observe the screen: The radio display might go blank momentarily while resetting.