Unfortunately downgrading is not available. Premier includes the ability to add investment income and expenses, and rental property income and expenses to your return. This includes things like bank interest, stocks, bonds, dividends, mutual funds, capital gains, etc... Once any of these are indicated by the answers you have given in the interview or by any carry-forwards from prior years during a transfer of information, the TurboTax software automatically upgrades the software.
Thank you for choosing TurboTax.