To change the face on your Apple Watch, follow these steps:

1. Wake up your Apple Watch by tapping the screen or pressing the Digital Crown.
2. Swipe left or right on the watch face to browse through the available faces.
3. Tap on the face you want to use to select it.
4. If you want to customize the selected face, press firmly on the screen to enter edit mode.
5. Use the Digital Crown to scroll through the available customization options, such as color, complications, and other features.
6. Once you’ve customized the face to your liking, press the Digital Crown again to save your changes.
7. To switch back to the default face, simply repeat the process and select the face you want to use.

Note that the steps may vary slightly depending on your Apple Watch model and the version of watchOS it’s running.