Apple Watch will notify you when there is an update. Tap "Update Tonight" in the notification, and then confirm on the iPhone that you want to update at night. Before going to bed, please make sure that the Apple Watch and iPhone are charged overnight to complete the update. To update manually, please follow these steps:

1. On the iPhone, open the watch application and click the My Watch tab.

2. click general > software update. Download the update. If you are asked to enter an iPhone password or an Apple Watch password, please enter the corresponding password.

3. Wait for the progress loop to be displayed on the Apple Watch. The update may take several minutes to an hour to complete.

4. When updating, please keep the Apple Watch connected to the charger. Don't restart iPhone or Apple Watch, and don't quit Watch App. After the update is completed, Apple Watch will restart itself.