What to do when you have the settlement check as the administrator of an Estate? The only immediate survivor lives abroad and has no visa.

This is a complex question with many parts.  You will need to open an Estate Account.  To do so you will need an EIN for the Estate.  The check can be deposited.  Creditors have nine months to submit claims, called a proof of claim, against the estate.  If there are no claims against the estate, then payment can be made.  I have distributed estates to beneficiaries that are not US citizens and do not live in the US.  There is no "closing" document for the estate unless you have a bond.  If you have a bond, then you need to get a release from the Beneficiary and file that release in order to get the bond released.