With the Customize dialog box open, do one of the following:
To edit a toolbar button image, right-click the button on the toolbar, and then click Edit Button Image on the shortcut menu.
To edit a menu command image, click the menu on the menu bar or toolbar, or click the shortcut menu that contains the command with the image you want to edit.
Right-click the menu command, and then click Edit Button Image on the shortcut menu.
Make the changes you want.
Note If you change the image for a command on a built-in menu (for example, the Edit menu), the new image appears in all views showing that menu with that command.