Here’s how you can update to watchOS 2. Open the Watch app on your
iPhone, go to “General” then “Software Update.” Apple should then
prompt you to update.
There’s no reason why you shouldn’t update to watchOS 2. In many
ways, it feels like the Apple Watch was in beta, and watchOS 2 is
the final version of Apple’s vision. Things load faster,
developers are going to take advantage of the new features and
everything is more reliable.