You'll need to locate and delete the 1099-MISC form that the income was generated on and delete it.
It is best to delete the 1099-MISC from that forms Summary screen. Here is how: Simply search for the form number (1099-MISC) in the search box and then click the "Jump-to" link in the search results to get to the Summary screen.
Or you can:
- Select My Account
- Select Tools
- Select Delete a form
- Find 1099-MISC and select delete