How and why?
Well, best to start with the why. I'm sure some of you will already know that I've no interest in the occult or in fortune telling - but I do enjoy card games and tarot is the best family of games in the world. At least, they're the ones I enjoy the most and to see them so neglected inspires both a sense of civic duty and a drive that is entirely self interested (I want more people to play with!).
And everyone needs a hobby.
How is rather a tough question. The games are, in some places, especially in France, already very mainstream - it is just us English speakers who are missing out. I can't believe that mainstream publishers would publish a book on the subject (or the Dummett and McLeod volumes wouldn't cost about £85 each), so that only really leaves the internet. The mainstream media only seems interested in the occult tarot which is, at least in the UK, already very mainstream.
The simple fact is, this is not a one man job. So, the plan is, build a website with all the rules and add a forum to enable a community to form, however small to start with. Host signature banners that members can use in other forums to bring folk here (I've trialled this in some 3d forums and had some good traffic from it!). Encourage them to spread the word in whatever diverse web communities they belong to. I'm trying to work out how to make little animated films that could be hosted on YouTube, perhaps with a view to building an introductory series of tutorials. There are probably many little strategies made possible by the internet - but, for now, it has to be little steps. I only have so much time.
With luck, from a small beginning and over a long time, there is the potential for word to spread. Perhaps I'm overly optimistic but I think it could happen. With availability of rules and cards, the potential is now there.
It is interesting, and contrary to my initial expectations, that occult tarotists/readers are generally (though not always) sympathic to my goal. After all, the two uses are not mutually exclusive. The people who have opposed my plans the most have been those who see the cards as somehow evil - Christians in particular. I have recently joined a games club in this area and been warned against talking of tarot games because the wife of one of the group's founders is a Catholic who will not approve.