E-filing will not work, no matter what the screens say. You have to print the amended return, sign it, and file it by mail. You and your spouse must both sign the Form 1040-X.
Attach copies of your spouse's W-2 forms and any of your spouse's 1099-R forms that have tax withheld.
Mail the amended return by certified mail with a return receipt, so that you get tracking and confirmation of delivery.
