Hone those photoshop/lightroom and writing skills at work, start a side business and when you've got clients and steady business, quit your primary job.

That's what I'm doing right now. I've already got a steady photography business and next year I'm expanding the operation by hiring my first employee who can work full time on the more trivial projects. I hope that in a few years I'll be able to quit my current primary job and work full-time in photography.