How can i do turbo tax free edition

Go to Turbotax web page, click on Help Link (Top) select Turbotax support, and type in Free File in search an enter, then select 1st choice Difference between IRS free file and and free addition and then click on Turbo Tax Free addition.  (keep in mind it only works on simple returns)

If you wish to go back to the free version of Turbo Tax, you would need to clear your return and start from scratch. 

To clear and start over, please follow the instructions here.