Recharacterizing your Roth IRA contributions for 2020 and 2021 will correct those excess contributions. Since you've already filed your 2020 tax return you'll need to amend that to show the resulting traditional IRA contribution.
Correcting the excess contribution for 2019 requires that you obtain a regular distribution of the amount of the 2019 excess with no adjustment for earnings. Your 2021 tax return will included Form 5329 showing that this regular distribution in 2021 eliminates the excess for 2021.
You'll file a 2019 Form 5329 to calculate and pay the excess-contribution penalty for 2019. Your amended 2020 tax return will include Form 5329 to again report and pay the excess-contribution penalty on the 2019 excess not corrected before the end of 2020.
