1. Open .xls spreadsheet in Excel.
2. Press Alt + F11 to view the macros.
3. A message tells you the macros are password protected.
4. Open the .xls file in Notepad++
5. Locate the three keys; CMG, DPB, and G.
6. Create a blank .xls document.
7. Password protect the macros with a password of your choice.
8. Open the new .xls file in Notepad++ as well.
9. Locate the exact same three keys.
10. Copy and paste the keys from the new file into the old file and save the file.
11. You have now effectively changed the password for accessing the macros of the original file.

Note: this method only works on the older .xls formats, not the newer .xlsx format.