In order to downgrade you may need to Clear & Start Over.
You can attempt to Clear & Start Over if you have not already registered the product.
Once you've cleared your return you should be brought back to the original screen that says, "Hi, ______! This is what we got you last year, lets start your 2016 return!"
Under this section is a hyperlink that
says, "see other products". You'll want to choose this. If you start for
free, and have information pulled in from last year, you'll be upgraded
to our PLUS Benefits program. You can avoid this by letting it run its
course and clicking continue once everything is in. After you click
continue you'll want to select that you do not want to include this and
you'd like to Start For Free.
If you are not able to Clear & Start Over, you can abandon the return you're already in and go to our Freedom Edition. You only have to qualify for one of the prerequisites to use the program.https://ttlc.intuit.com/replies/3301359