Philosophy is mostly about personal happiness -– not social revolution. It's mostly about changing and improving yourself -– not the world.
But if for some strange reason you do want to focus large parts of your sacred and irreplaceable life upon enhancing mankind then realize that, ironically enough, the best way to go about this is probably not by direct teaching and intellectual seduction but by being a paragon of virtue. You probably need to become a shining avatar and exemplar to others, and then you can teach people how to be happy in the most effective and persuasive way possible: by example.
Pretty much everyone is a genius at social revolution. Pretty much everyone is a legend in his own mind. Utopian dreams basically infect us all.
Even Plato -- a truly great thinker and societal analyst -- evidently considered himself to be brilliant at changing the world. So what did this genius advocate? Making political thinkers study geography -- for nine years! And imposing upon everyone a dictatorship. Nice, eh?
It's easy to radically reform society. Or at least to champion such. It's far harder to radically reform and uplift yourself. To do so even slightly usually proves to be an almost impossible mountain to climb.
So most people barely even try this annoying, irritating, exasperating, infuriating task. Instead of letting us all alone, and leaving us in peace to live our lives as we wish, most folks take the easy way out and focus the majority of their efforts on improving their fellow man and fomenting world revolution.
Pathetic.