I need to amend 2016 return not yet mailed in.

[Jimesa · Accepted solution]

Since you haven't mailed your return yet, you can "unlock" it by following the steps below to change your filing from file by mail to e-file. Once your filing method has changed then you can make your changes and switch your filing method back to file by mail. Please see below for instructions on how to change your filing method. https://ttlc.intuit.com/replies/3985787