// PUT /admin/members/{id}/
{
    "members": [
        {
            "name": "Jamie II"
        }
    ]
}

PUT /admin/members/{id}/
All writable fields of a member can be updated. It’s recommended to perform a GET request to fetch the latest data before updating a member. A minimal example for updating the name of a member. 
// PUT /admin/members/{id}/
{
    "members": [
        {
            "name": "Jamie II"
        }
    ]
}