How do i claim deceased refund with form 1310?

[Carl]

You have to print, sign and mail the tax return with the form 1310 to the IRS, along with any other supporting documents (if necessary) to prove that you are legally entitled to the refund of the deceased. Get the 1310 at https://www.irs.gov/pub/irs-pdf/f1310.pdf
So if you are the legally appointed/recognized administrator of the estate of the deceased, you'll need to include copies of the court documents to prove that. Otherwise, the IRS will not make the refund check payable to you.