If you want to remove a macro from a shortcut key in Excel, follow these steps:
In the Save changes in: list, select the workbook where you want to store the modified shortcut keys. If you want to share your customized keyboard shortcuts with others, save them in your Personal Macro Workbook so that the shortcuts are available whenever you start Excel.
Click (remove). The currently assigned shortcut key is removed from the list of Shortcut keys.