@tvbotham - you'll need to complete form 1310.
https://www.irs.gov/pub/irs-pdf/f1310.pdf
since your father has passed, the IRS needs documentation of who is signing his personal tax return and with what authority. That way they know that the refund can indeed be sent to you without being fraud. (I imagine they check against the SS records to confirm the death in any event)
you can simply deposit the check into the Estate checking account, even if made out to your father (or even to you). It's not taxable income - it is a refund.