If you're eligible for an update and don't want to wait for the watch to do this automatically, and don't want to use Garmin Express.
You need to have already set up WiFi syncing.
- Long press the Light button and select the Sync function (arrows pointing round in a circle).
- Whilst it's doing that, swipe up to activate WiFi sync.
- Wait for the sync animation in the watch face to finish.
- Long press Up button, go into settings, System, Software Update.
- The update should be available for you to install.
This will only work if you're already part of the current roll out percentage or (for betas) have signed up to the beta program.