To update a relationship, you must have access to the parent person.
personIdof an existing relationship cannot be altered after it is created.
Updating Email Addresses, Phones, and Addresses
Sending an array of email address, phone, or address objects will overwrite the values that are already present for a relationship. (e.g., If there are two emails listed and you send one new email address, the two emails are removed and just the new one is saved.)
If you want to maintain existing email address, phone, and/or address objects while adding new ones, you must resend the current list and add any new ones to that array.
(If these arrays are left blank, no changes are made.)