How to delete a macro in Excel

Macros in Excel are programs that are written in a language called VBA (Visual Basic for Applications).  These programs are written to automate tasks in Excel, particularly those that are performed repeatedly.  Macros are usually saved with a workbook and if the workbook has the extension .xlsm, then it has a macro associated with it. If a macro is not being used, it should be deleted as it will increase the size of the file.