Using the Trek Flare RT rear bike light is a breeze. First, make sure it's fully charged. You can then attach it securely to the rear of your bike. When you start your ride, the light's integrated sensor will automatically adjust the brightness based on the environment. Whether it's a sunny day or a dark evening, you'll be visible. As for maintenance, keep the light clean by wiping it with a soft cloth regularly. Avoid exposing it to extreme temperatures and moisture. If you're not using it for a long time, store it in a dry place. Also, check the charge level before each ride to ensure it works properly.