For prior years you have to buy the Desktop program. You can only buy the download for prior years. You have to buy a separate program for each year. They only sell the last 3 years. You need a full Windows or Mac computer to install it on. Buy the download here
https://turbotax.intuit.com/personal-taxes/past-years-products/
If you don't have the original Turbo Tax .tax file you have to first recreate the actual wrong original return. You can use the Forms Mode. Then when it matches each line that you really filed you have to tell Turbo Tax you will mail it so it thinks it was filed. Then you can amend it. You will have to print and mail amended returns.
The how to amend it. If you don't see a button for Need to Amend a Filed Return? on your home screen then you can get to it here. Go to:
Federal Taxes -or- Personal (for H&B)
Other Tax Situations
last section, Other Tax Forms
Amend A Return - Click the Start or Update button
