I filed a paid tax return last year. This year I want to file the free version. Turbo tax is NOT allowing me to do this. How do I change. I have signed in already ?

Try this -

Clear your return and start over with the Free Edition.  Click on Tax Tools on the left side of the screen.  Click on Clear & Start Over

Let the program use Plus to pull your 2016 data and click on Get Started.  On the screen that says "Things are looking good!" click on Continue.  The next screen should give you the options for Free, Plus and Deluxe.  Scroll down to the bottom of the screen and under the Free edition click on the Start Over button.   Beneath the Start Over button it shows -  Delete your info and start from scratch

See Screenshot 

The program will remove all your prior year information and will land on the screen that states Are you sure?  Click on the button Start over from scratch  

See Screenshot

exactly. extortation