When an executor is appointed after a valid Section 622(c)(3) or (4) election has been made, the election can be amended by filing Form 8855, Application for Taxpayer Identification Number for Estate and Trusts, with the Internal Revenue Service (IRS). The amended election must be filed within 60 days after the appointment of the executor or alternate payee. It is recommended to consult with a tax professional to ensure proper completion and filing of the form.