You do NOT amend a return that was never accepted or processed. You need to fix the reason for the rejection which is for the prior year AGI and it is not needed for a mailed in return ... so just print, ink sign and mail in the prior year return.
To access your current or prior year tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on Download/print return (PDF) or Download .tax file
