"do I also file an amended 2023 tax return to pay tax on the earned income for the excess contribution?"
No. Because the corrective distribution is being made after the due date of your 2023 tax return, the corrective distributions need to be regular distributions of exactly $6,500 each, with no adjustment for earnings. The earnings are permitted to remain in the Roth IRAs when the excess is removed after the due date of the tax return. Tell the financial institution nothing about this distribution being to correct an excess contribution, otherwise they might mistakenly try to process the distribution as a return of contribution before the due date of the tax return.
2024 is different because you are removing the 2024 contributions before the due date of the corresponding tax return. In the 2024 case, earnings are required to be distributed and the are taxable on your 2024 tax return to avoiding the 6% excess-contribution penalty on the 2024 excess contribution.
Because the excess contributions made fore 2023 were not corrected before the end of 2024, you must still show those as overcontributions for prior years when preparing your 2024 tax return. With the 2024 excess contributions corrected before the due date of the tax return, only the excess contributions made for 2023 will remain on your 2024 tax return to be subject to the 6% penalties on 2024 Form 5329. Those penalties will disappear on your 2025 tax return when you report the regular distributions.
