If you are using the TurboTax desktop editions, then you need to open the 2024 TurboTax program. After the program is opened you need to Continue the 2024 tax return that needs to be amended. Then -
Click on Federal Taxes (Personal using Home & Business)
Click on Other Tax Situations
Under Other Tax Forms
On Amend a return, click on the start button
If you are using the TurboTax online editions -
To access your current or prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents. Click on the Year and Click on Amend (change) return
