I am a developer so I have it installed. YouTube probably is littered with video on installing the beta without developer account, but frankly, it's not worth the trouble. For one thing, there's a risk that your watch will be bricked during the upgrade (mine froze about 75% of the way), there's no way to downgrade, it's buggy, battery will probably drain faster, and there are only few new user facing features (nightstand, email reply, a couple of new watch faces, time machine complication control).