To set up heart rate notifications, go to the Apple Watch app on your iPhone, tap My Watch, tap Heart, tap High Heart Rate and choose Beats Per Minute, tap Low Heart Rate and choose a BPM. For ...

Make sure Apple Watch and old iPhone are updated and synced to iCloud > back up old phone > set up new phone. When asked to use Apple Watch, select Continue > keep devices close > follow on-screen ...

Erase your Apple Watch. On the Watch, go to Settings > General > Reset > Erase All Content and Settings. Follow the on-screen instructions. Set up your new iPhone, if you haven't already done so.