Selling Business, While Keeping One...Help!

I have a service based businesses that has been operating for over 6 years and it does well. I opened a second location a month ago, so obviously the numbers are not quite there yet, but of course we have projections. I am wanting to move out of state and had hopes of selling both locations, but that's probably not possible with the second one. That being said we are going to sell the first. The potential new owners do not want us taking any of their customers (although that's hard since many bounce between the two). They would like to retain me for awhile so they continue keeping it a success. How should we move forward, especially with branding, social media, customer lists?

Thanks!