How do I downgrade to a less expensive version of turbo tax? I upgraded too much by accident last year. I only see options to upgrade to more expensive versions of the service.

Clear the return and start over with Free and then upgrade if needed.

Looks like you are in the highest version, Self Employed version.  You can try to downgrade but you have to clear and start over

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-online/00/26444

Or There is also The Turbo Tax Free File program which is free for federal and state.  And has more forms than the Federal Free Edition, like Schedules A, B, C , D, E, F, EIC, H, K-1, SE,  etc.

To qualify for the Free File website  you just need to meet one of these 3 things.

AGI $39,000 or less.

Active duty military with AGI of $72,000 or less

OR qualify for EIC (earned income credit.)

In order to use the Free File program, you have to start it at a special website.  Click on Sign in at the top right.  It may let you continue your return so you don't have to start over.

https://freefile.intuit.com/