It appears from your post that you're using TurboTax Deluxe, which is the lowest PAID program that TurboTax online offers. The only "lower" option would be the Free Edition.
Nevertheless, the way to downgrade your selected program is to use the "Clear and Start Over" feature. See the information below from a TurboTax FAQ for instructions. Please note that all of your data you've entered will be cleared.
"Can I downgrade to a lower-priced version of TurboTax online?"
https://ttlc.intuit.com/replies/3288495