This is a complete guide to calibrate your OEM touchscreen with your Hamilton Upgrade Kit installed. It is a good practice to do this after installing your Hamilton Upgrade Kit.
How to disconnect CarPlay properly:
Disconnect CarPlay by swiping down from control center and touching your WiFi icon on your phone. Your iPhone will ask you "Do you want disconnect CarPlay?" > Click "Disconnect" > Then immediately turn off your iPhone's BT to prevent CarPlay from reconnecting.
(1.a) Android Auto disconnects by turning off phone's BT.
This video shows how to calibrate your screen:
Tap repeatedly in the center of the screen (in an area not touching any apps) until the calibrate page appears. Follow the prompts twice to calibrate your screen.