There are two ways to do this.
First:
Delete a Form in on-line
A. Go to Tools in left side of screen and click on Tools
B. A box titled: Tool Center will open and below the 3 boxes is: Other helpful Links…
C. Click on the 3rdt one: Delete a Form
D. Go to Form you need to delete and click on it and confirm ==Look for 1099R
2nd method
Go to Federal Taxes
Wages and Income
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=Then Delete it.