Self employed

You can go back to your Schedule C and manually reduce the income that is double-reported.  You would need to go back to your Schedule C and correct this:

1. Open or continue your return
2. Locate the Schedule C section
3. Go to Schedule C
4. Under the business you need to review, go to Review
5. Make changes to the income as needed

If you have duplicate forms 1099-MISC, then you can also delete the duplicate form directly.  See the TurboTax help articles below for more information:

How do I delete a tax return that was created in TurboTax Desktop for Windows?

How do I view and delete forms in TurboTax Online?