Revolution; and then true socialism
Unfortunately, the traditional Marxist-Lenist mechanics of winning a violent revolution tends to make achieving actual socialism difficult.
First you have to get a few billion people murderously angry with their neighbours and sisters and brothers; then you have to set up a centralised command-authority to make all those murderously angry people kill the right people and not the wrong ones, and train them how to kill efficiently and without moral qualms; then you have to deploy that command authority to take a burned out, smoking wreck of a world filled with well-trained, still murderously angry but now hungry killers, and make them not kill you. Easiest way to do that is to intimidate them by being really nasty, nastier than the old government they got angry enough with to overthrow.
Congratulations! Now you've got a world filled with smoking wreckage and scared, emotionally scarred angry people who are good at lying to your face so you don't kill them, but who still remember how much better things were before the revolution and the civil war. And now you get to use those people to create an open, loving, honest, trusting society where everyone does things for everyone else out of the goodness of their heart.