Here's the response I was typing when the flagging happened. (I happened to capture it when I saw that something was happening to your original post.):
Assuming that you are not eligible to treat this excess as a contribution for 2020, there is no way to avoid an additional 6% penalty for 2020. If you are also unable to treat this excess as a contribution for 2021, correcting this excess contribution after the due date of your 2019 tax return requires you to take a regular distribution of exactly the amount of the excess (with no adjustment for investment gain or loss) before the end of 2021. Your 2021 tax return will include Form 5329 Part IV to show that the excess has been removed for 2021 and beyond.
If you were eligible to contribute to a Roth IRA for 2020 and did so, you could obtain a return of contribution of that contribution made for 2020 to make room to apply as a 2020 contribution some or all of the excess carried in from 2019. None of the excess itself is permitted to be removed by a return of contribution before the due date of your 2020 tax return.
