Imageco,
No shame in trying to provide for your family! In fact, you led the way for a while there creating all those local directories. Not a good approach nowadays, but it worked for a while.
_What is the best way for me to do this? _
I'm going to point you to two resources created by Miriam Ellis, a local expert at Moz and a person who has tremendous insight and is willing to share her wisdom with anyone who asks.
Moz Local Checklist - This first one looks at the type of business you have and Google Guidelines to arrive at the best strategy for your Google My Business listing and content. It also inventories all the other steps that will need to be taken to achieve local SEO success and provides links to other helpful resources and a checklist.
Local Landing Page - Inspiration, tips, guidelines, and a template for creating truly valuable local content.
Do I need to delete everything and start completely from scratch or is there a less extreme approach to making this kind of transition?
I recommend you inventory your existing content after you've reviewed the resources above and then decide whether to keep, change, or delete them. I would expect they'll be helpful in coming up with "truly valuable local content".
And once I do make these changes what might be the time frame for turning up better locally?
As I'm sure you well know, local SEO takes time too. How long it will take is going to depend on your starting point relative to your competition. If you want to set a ballpark, I'd say a year. It's a ballpark. You should start showing up on maps sooner than that, but you may not make it into the local three-pack for some time after that. Much will depend on the strength of your competition and the health of your existing website. Local and organic are intertwined. The latest local search ranking factors study published by Moz found that the second most influential contribution to local rankings (second only to your Google My Business listing) was link signals - not on-page, not citations, and not reviews.
Good luck Imageco! Work hard. You'll get there.