If you would like to edit your employee's termination information, go to Employees>click Employee>Termination Information.  

Click the Termination Information you would like to edit.  The Edit Termination Information box will pop up.  Make the necessary edits and click Save.  Otherwise, click Cancel.

Once you make an edit to an employee's termination information, you will need to regenerate payroll for the edits to reflect in payroll.

Note: Once leave conversion has been run in an account, there is no way to undo the leave conversion (ie. deleting payroll, regenerating payroll, deleting leave credit, etc.)