https://ttlc.intuit.com/turbotax-support/en-us/help-article/prior-year-tax-return/access-prior-year-return/L7opE9vDA_US_en_US?uid=lnsayf2f
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...