To delete sales entries, or any downloaded data in MyCostPro, please follow these specific steps.
Click the black FULL SCREEN button near the top right, this will display the row numbering and ribbon bar, etc.
Select the row, or multiple rows (be sure it is selecting the entire row(s) by selecting from the row numbering area.)
Right click one of the row numbers that you have selected, pick 'Delete' from the drop down list
Let me know if you have any trouble or questions about this!