Do you have the software that prepared your original return and the submitted .tax file in a safe place on disk? That offers the easiest way, avoiding reentry of entire tax return.
Do you have a paper/PDF copy of the original return, or an IRS transcript?
You already know all about 1040-X from prior experience.
1040-X reports the differences between original and correct
Reply back if the answers are respectively, NO, YES, and you want a manual process.
@N7075g
