Only you can do that ... to go down to a lower version you will have to clear everything and start over .... but if you have registered the account or used the LIVE feature you cannot clear this account.
If you have not yet filed :
How to see your fees
https://ttlc.intuit.com/questions/2565973-how-do-i-review-my-fees-in-turbotax-onlineFor help with fees
https://ttlc.intuit.com/questions/1901213-what-can-i-do-to-reduce-my-feesHow to remove the Pay from your Refund fee
https://ttlc.intuit.com/questions/1900517-how-do-i-remove-refund-processing-fees-in-turbotax-online-...
