I was gonna transcribe the segment but I ain't got time for that.
Basically, it's automatic. You can't switch to Night Mode manually. It shows you how long the exposure is going to be, for example 3 seconds. So you know to hold still for three seconds to capture the best photo. It will also use the motion sensors to detect if you're holding it in your hand or not, and if it's on something like a tripod, you can extend the capture even longer, think 30 seconds to one minute to really get those shots.