1. Open Excel 2003 and select the workbook that will use the macro. Click 'File' on the menu bar and select 'Open.' Browse your files and locate the workbook. Click the workbook and select 'Open.'
2. Click 'Tools' on the menu bar and select 'Macro.' Select 'Macros.' Select your macro from the list of available macros.
3. Click 'Run.' The macro is executed on the workbook.