This Pixel-exclusive phone app is a revamped version of Google's existing dialer
It's an entire version number ahead of the one you can find on the Google Play Store. It includes a number of cool new features, including an incoming call screen that matches the new Google Duo video chat app, and it can be installed on compatible devices if you're interested in getting a taste of the Pixel experience.
the first thing you'll need to do is download the new Google Phone APK. Once you've done that, tap the Download complete notification, then hit "Install" when prompted. If you don't see any error messages, you'll be good to go.