Amending my return

See this TurboTax support FAQ for amending a 2018 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27579

To enter a form 1099-R -

• Click on Federal Taxes (Personal using Home and Business)
  Click on Wages and Income (Personal Income using Home and Business)
  Click on I'll choose what I work on (if shown)
  Scroll down to Retirement Plans and Social Security
  On IRA, 401(k), Pension Plan Withdrawals (1099-R), click the start or update button

Or enter 1099-r in the Search box located in the upper right of the program screen. Click on Jump to 1099-R

how do I change certain portions of my 2017 return?