how I can change to turbo tax for free?

In TurboTax Online, you may be able to Switch Products or Clear Data and Start Over.

• Switch Products may be found in the lower left hand corner of the screen if it is available.
• Down the left side of the screen, click Tax Tools.
• Down the left side of the screen, click Tools.
• Select Clear and start over in the center of the screen.

See this TurboTax Help.

As long as you have not

• submitted payment, 
• deducted the TurboTax fee from your refund, or 
• registered your product, 

you may erase your return and start from scratch in TurboTax Online. If you have done any of these things, you will need to manually edit your return.

To erase your return and start over in TurboTax Online:

1. Sign in to TurboTax and open or continue your return, if you haven’t already.
2. Select Tax Tools from the left menu, then Clear & Start Over.
3. Answer Yes to confirm.