Mailbox Sensor Installation

I received my new mailbox sensor, but there were no installation instructions included. I searched the Ring website and internet and also could not find anything. - Does anyone know what the switch is inside of the battery box and if I need to change it? - Is the round grommet placed on the cable end at the box, or somewhere else? - Does the sensor need to be placed like in the photos on the door, or can it be placed anywhere within the mailbox if the external antenna is used? Anything else I need to know? Thanks, Mitch