It appears from your post that you're already in the Premier edition.
The only way to downgrade your online product is to use the "Clear and Start Over" feature. This will delete any data entry you've already made, and will likely return you to the Free Edition to begin with. From there, you'll have to upgrade to the Deluxe edition if that's the edition you wish to use. See more info below.
https://ttlc.intuit.com/replies/3288495
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
