How to use Android Wear's new offline music and Bluetooth headphone features

Google latest Android Wear update lets you use your smartwatch as a standalone audio player, with no smartphone tethering required. But how, exactly, do you get music tracks into your watch's onboard storage? And how do you pair your watch to Bluetooth headphones or earbuds? Google doesn't have clear documentation in the Android Wear app, so I'll show you how to do it here. First, make sure you're running Android Wear 4.4W.2. (You can find this system info by going to Settings>About on your watc...