|Actually, it's easier than Mike described.|
If you try to save a workbook with macros as a .xlsx, Excel will warn you about the macros, but give you the following option:
"To continue saving as a macro free workbook, click Yes".
The code will stay in the workbook while it is still open, but once you close it and re-open the .xlsx version, the macros will be gone.
Click Here Before Posting Data or VBA Code ---> How To Post Data or Code.