Roughly:
Reach out to them saying "it's been a while" and you're just touching base.
Then try to find out what their frustrations are, what they've tried to solve it, why it didn't work, what they would do to get the problem solved, and what one big question they'd want to get answered.
Then build a product around that need and do an internal launch preceded by 3 vids that already give them great value and part of the solutions.
Build an opt-in page and drive the people from the list there.
Host a free webinar.
Then open cart.
then sell your product.
the day before your cart closes, email people from your dorment list, remind them the cart is closing and they can still get the product.
repeat around 3 and 1 hr before closing cart.
Close cart