There isn't a button to Edit or Revisit it?
Edit a 1099R under
Federal Taxes
Wages & Income
Then scroll way down to Retirement Plans and Social Security
Then IRA, 401(k), Pension Plan Withdrawals (1099-R) – Click Update or Revisit
IMPORTANT:
If you edit or review a 1099R it does not keep your answers from before but resets them to the defaults. Then you have to go through and answer them all again. So be sure to go all the way to the end of the 1099R section. They are right unless you go back.