To customize the commands, which are available on the several toolbars and in the menus, you have to open the customization dialog and select the 'Commands' page.
When this page is active, you can simply drag & drop commands from one menu to another one, from one toolbar to another one, from a toolbar to a menu and vice versa. Further on, you can drag & drop commands, not already available on the toolbars or the menus from the 'Commands' list of the dialog page.
You can also change the text and/or the image of menu items and toolbar buttons. Simply select a menu item or a button, right click on it and choose 'Button Appearance...'.
The controls of the page are having the following meaning: