Can’t install new update

What happens when you try to update your Apple Watch?

Please take a look at the following resource, spefically the content under the heading "If you need help updating"

Update your Apple Watch – Apple Support (UK)

Let me know how you get on!

Try to update from the watch itself.

Restart the watch.

Place the watch on the charger.

Make sure that your watch is connected to wifi.

On your watch, open the Settings app.

Tap General > Software Update.

Tap Install if a software update is available, then follow the onscreen instructions.