amending tax filing status

I need to amend my 2023 tax transcript returns to change my filing status from single to married filing separately. The prepare who file my original return want to charge $200 for this amendment and mentioned it can only be mailed which may also delay my process, So I will prefer to handle it myself to save the cost and time 

- Am not sure of what software to purchase as am not sure which one did, he use to file my tax?

- since I did not file the original return myself, how can I retrieve the necessary information into the new software?