Factory Reset puts Control Center back into a pristine state where it is ready to go through the setup process. The process erases all configuration data (Devices, Watchlists, IR codes, Network settings, etc). You can factory reset your Control Center by two methods:
First you can navigate to Settings > Factory Reset, then press and hold the MENU button:
Alternatively, you may execute a factory reset from the single button on top of Control Center using the following button press sequence: one quick press, then one long press and hold(~20 seconds). The LED will blink once after holding the button down for 10 seconds and again at 20 seconds. Release the button after the 20 second LED blink. If the LED does not blink at ~20 seconds you should release the button and try the sequence again.