Post-scarcity/How do we get from here to there?
In a sentence: by increasing the amount and quality of physical goods and information available openly until it makes no sense for anyone to rely on anything else.
Imagine a world where you can grow all your own food in a small greenhouse, in a largely automated system. Your water falls freely from the sky or wells up from the earth and is filtered and cleaned automatically. Any time you want a new gizmo, you can find a design online and make it without difficulty. The kids have access to the best education ever conceived, for free. You have abundant free energy from the sky. What need have to you engage with the monetary economy?
The situation sketched above is not a vision of the future at all; it is possible now. All these things are already available for free, but few people are aware of it, fewer are doing it and it takes too much work and requires too many compromises. Right now, open-source hardware is, in some cases, of lower quality than commercial hardware, but is is early days. Manufacturing currently is too costly, labour-intensive and inflexible as well as requiring too much complex machinery and expertise. Wonderful open educational resources are out there, but are not properly organized into a comprehensive, easy-to-navigate curriculum. And you can grow all your own food, but it's tough work. Easier, then, to work for a living and perpetuate the money-system that synthesizes scarcity.
The way to bring about a global post-scarcity economy and to make it the only game in town is simply to add to the commonly-held resources of mankind until they become indisputably better than, or as good as, commercial resources. Learn how to grow your own food and give the seeds and the exact method of growing away for free on the Internet. Contribute to open-source educational materials. If you can program, contribute to open-source software projects. If you have any idea about engineering, contribute to open-source hardware projects. Use open resources yourself, note whatever problems you have with them, and correct them or else bring them to the attention of an expert who can correct them. Bring open projects to the attention of architects, researchers, engineers and programmers. Print fliers about an open-source project like Fab Labs and RepLab and drop them in university engineering lecture halls. Get involved in open-source robotics 
and very practical hands-on projects like those being developed by the Open Source Ecology team. If you know about a lot about chemistry or Egyptian history or flamingoes, improve Wikipedia or open educational material. If you can sew and make clothes, post sewing patterns online. Focus on quality. You don't have to do all the contribution yourself; get your friends to help. Even get your acquaintances to help. Connect those with design skill to those with design projects. Study whatever you're passionate about and think how you can use it to add value to all mankind.
By adding to this pool of resources, you make it easier for people to build their own abundance. And the easier it becomes to live a life of abundance and leisure without any need for the monetary economy, the more people will do it. Thousands of people have dropped out of the monetary economy onto organic farms, but that simple, pastoral lifestyle is not to everyone's taste. Post-scarcity will not come about until it is possible to live a life of abundance and leisure outside of the economic system without making sacrifices in their quality of life.
Lead by example. Use the information available to you to find a solution to your needs of water and energy and food and shelter. Once you have solved your basic needs without reliance on the monetary system, move it up a notch and solve your wants of clothes and furniture and electronics without reliance on the monetary system. And always contribute, contribute. Of course, like some strange tribe, you will need to come to an agreement to trade with the civilized men around you and co-exist with them. You will need money at first, but as you work things out you will become more and more independent, more and more resilient. And keep contributing, contributing, making it easier for others to follow your trail. Don't do all this alone; do it with your friends. It's much more fun that way.
Social change doesn't come by decree from the politicians' halls. It always comes from the bottom up, from the young vibrant minds who see clearly and say, "I can see a better way to do things". That is how post-scarcity must come about: from the kids. What if a million or ten million kids around the world dropped out of the monetary system and started living their own lives, able to make for themselves all the things to fulfil their usual needs, and passing around, among a global network, the things to fulfil their unusual needs. And what if the kids still in the monetary system started to see that the drop-outs were better-educated, healthier, had all this leisure and free time and spent it making rhythms and forging art and were having so much more fun than anyone could in a rat-race scene?
Many grass-roots and open-source type projects are making a real difference in the world right now, so join an existing one or inspire others and start your own. What have you got to lose?
