Are you saying you want to completely delete Schedule F and associated forms? Or that you only want to delete a particular entry on the Schedule F while keeping the Schedule F for other entries? If the latter, more info is needed.
If you don't need a Schedule F at all, then in Online TurboTax you can go to the left menu column and click on TAX TOOLS, then subtab TOOLS. In the Tools window, there is a link "Delete a form". Be very careful that you don't delete any forms you need.