Are you currently doing anything with that segment of the market?
First of all its a s-l-o-w process, at best you are planting seeds for the future. It's battle of attrition, can you out last you competition in consistently making your brand known.
I have a little more time than you and I have more than 2-dozen marketing projects I'm at some stage with.
Are you looking at face to face in the trenches materials: Business cards, brochure, a company bi- who you are, what services you offer, specialty products, pens, pads, mugs, etc.
From your home: into letter, business card, brochure, postcards and or newsletter.
Be consistant, keep in front of them. All your competition is asking for their businees too, so you have to continually remind them why they need to call you.
Experience
Training
Response
Equipment