To transfer a business to another individual you'll want to do the following.
Change the business email to the new email via Settings > General Setup
Update business entity information from Settings > Tax Settings
Add/remove new or departing admin/staff members in Settings > Staff Accounts
If you're changing Stripe accounts, send an email to [email protected] requesting the existing Stripe account be disconnected. You'll want to make this request as close to the changeover data as possible. Maybe even on the same day.