@Marianne526 When you post looking for advice, it's a good idea to make the situation clear- as you can see, the responders here, all of whom are experienced hosts, are just playing a guessing game as to what you actually meant.
And "What do I do with all their future guests that under the agreement they are supposed to be honored'" - If the accounts are under your name, the future guests with standing bookings aren't "their" guests, they are yours. You can't just pass on guests to a new manager or back to the owner, who hasn't been dealing with guests at all, as if they are a piece of furniture. You wanted the listings in your name so that you received the reviews and had control of things, guests book based on the reviews, which are more of the host than the property itself, so it is you who are abandoning those guests. The owners are not responsible for the bookings you accepted, you are.