To update the software on your Apple Watch:
• Update your iPhone to the latest version of iOS.
• Make sure your Apple Watch is on its charger and has at least a 50 percent charge.
• Connect your iPhone to Wi-Fi.
• Keep your iPhone next to your Apple Watch to make sure they’re in range.
Update your Apple Watch
1. Keep your Apple Watch on its charger until the update completes.
2. On your iPhone, open the Apple Watch app, tap the My Watch tab, then tap General > Software Update.
3. Download the update. If asked for your iPhone passcode or Apple Watch passcode, enter it.
4. Wait for the progress wheel to appear on your Apple Watch. It could take from several minutes to an hour for the update to complete.
Leave your Apple Watch on the charger while the update completes. Don’t restart your iPhone or Apple Watch, and don’t quit the Apple Watch app. When the update completes, your Apple Watch will restart on its own.
For information on the security content of Apple software updates, visit https://support.apple.com/kb/HT201222
MacDailyNews Take: Worked perfectly on multiple Apple Watch units here (Apple Watch Series 2 and Apple Watch Nike+).