if you want to downgrade versions, you may do so by following these steps: Downgrading Turbo Tax Versions

However please keep in mind that once you attempt to enter information that is not supported by the Free Edition of Turbo Tax, the system will prompt you to upgrade to the most suitable version. The  product guide below details the various options; you may click on the blue links within the FAQ to learn more about each version and the tax situation it supports.

Turbo Tax Versions

If you *filed* then  it is too late to change anything unless it rejects.    But once you pay or register then downgrading is not longer possible.