Today, Android Wear build KMV78Y is rolling out to the Samsung Gear live, which is was also released to the LG G Watch too.
The update is staged, so it will show up on your watch whenever it shows up. However, the OTA URL has been captured and can be found on XDA (Source link below). Simply download the update and install it with ADB sideload. There are no guarantees this will go off without a hitch, though. Waiting for the real OTA is probably reasonable, especially considering we don't know what this update does yet.