Earlier quoted context omitted.
What exactly do you need answered about the "how"?
"network with people who will pay you to freelance." That.
If you don't know where else to start, go to a local user group, or better yet, present at one. It only takes one visit to see how low the standard is at most of these things, the organizers are usually just happy to have someone willing to present, so you don't have to worry about not having anything substantial or good to present.
I had a full-time consulting income for several years predominantly from just following ads for freelancers on Craigslist, in a relatively pedestrian market. I didn't even do the basic networking stuff that is still a very good idea. The hardest part of breaking in is having the gumption to get it kicked off.