If a farm is sold, the ownership of the farm account should be transferred to the new owners.
There is no need to setup a new account.
Ideally this process should be documented in the sale and purchase agreement.
The existing (or previous) owner can invite the new owners to accept Owner access to the farm account
Once the new Owners have accepted that invitation, they can either remove the previous Owners access themselves or contact the Overseer Helpdesk and ask us to remove the access for the previous owners. This can be done from the dropdown menu within OverseerFM: