If the tax return was filed and accepted then the only way to change the tax return is to amend it. Before amending you should wait for the return to be processed so that the refund has been received or the taxes owed have been paid.
See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...
If the tax return has Not been filed then you can change the return using the TurboTax desktop editions for prior years. You will need the tax data file for the year that needs to be changed and open the file using the TurboTax software for that year. Prior year tax returns can only be printed and mailed using TurboTax, they cannot be e-filed.
Go to this TurboTax website for prior year desktop editions - https://turbotax.intuit.com/personal-taxes/past-years-products/
