You don't. Delete the devices from your account, and then reset them. Let the new owners set them up so that they get familiar with them, and the tstat will now start learning their schedule. If you want to be nice, leave them written setup instructions.
I apologize for my late response and thank you for all of your patience while waiting for a reply. I definitely understand how frustrating your situation must be, and I wanted to make sure that your concern was acknowledged. Do you still need help with this issue? I know that there's been a delay in response since you posted.