How to switch setup from in my home to in sitters home?

Rover support can modify the reservation for you.

As long as the client and sitter agree upon where the services will be provided and what services, specifically will be provided, it isn't critical that user profiles and reservations are correct (as far as in whose home the pet will be).

If a sitter wants to add Dog Hosting (in their home) they can do so by clicking: Profile >> Dog Sitting Profile >> Services & Rates >> Add Dog Hosting to my sitter profile. They can then cancel the stay and send the booking request through that portion of their profile.

I would suggest that stays in the clients home and in the sitters home are just booked separately and the instructions/details sections updated to reflect where the stay will take place. Since each booking request includes customizable pricing, the client and sitter can decide what the difference will be between the two types of stays and update the quote accordingly. This will help to differentiate between the different types of stays and make it easy to book without worrying about what the client and sitter profile say.