Right click a blank spot in the Toolbar area. Click "Control Toolbox"

Click the image of a button

Click and drag in your worksheet where you want the button

Double click the button  - this will take you to the VBA editor and
generate a sub

Type "ActiveWorkbook.Close" without the quotes

Close the VBA Editor window

Click the top left button in the control toolbox to take you out of design
mode

Close the control toolbox