Select the cells containing the numbers. If you want to remove the dashes from the entire worksheet, click the Select All button, which is the rectangle between A and 1 in the upper left of the worksheet.To select an entire row or column, click on the number or letter pertaining to that row or column.n Excel 2003 or earlier, go to the Format menu and click Cells.. Go to the Number tab of the Format Cells dialog box. Select Number in the Category box. Change Decimal Places to 0 and click OK.. Open the Find and Replace dialog while the cells are still selected.