To switch to TurboTax Deluxe you will need to clear and start over.
In TurboTax Online, you can erase your return and start from scratch as long as you haven't submitted payment, deducted the TurboTax fee from your refund, or registered.
If you haven't already done so, sign in at TurboTax.com and select the Take me to my return button.
On the welcome back screen, in the left-side menu, select Tax Tools, and then Clear & Start Over (select the menu icon in the upper-left corner if you don't see this menu).
Answer Yes in the pop-up to confirm.
If you are using TurboTax CD/Download desktop version of Home & Business and wish to downgrade, you'll have to call in for assistance with customer support. The steps for downgrading online do not apply to desktop products. Go here What is the TurboTax phone number? for the phone number.