Customize KDE Menu with KDE Menu Editor
If the minor changes described in the previous section aren't enough to customize the menu in KDE to your liking, click the Edit K Menu button to open the KDE Menu Editor dialog, where you can make more changes to the list of menu items and submenus in your KDE menu:
The KDE Menu Editor dialog contains a list of all the submenus and menu items you currently have. You can edit existing menu items and submenus, if you click them on the list in the left pane. When you click a submenu, it will display all the menu items in it and you can edit them from the dialog in the right pane.
Depending on your access permissions (i.e. if you are logged in as root or as an ordinary user), different options will be enabled. The options you can edit are the name of the menu, its description, comment, command, etc. If you are logged in as root, you will be able to set the work path, whether to run in terminal or not, and the user who will be able to run it (besides you).
As you see, there is quite a lot you can do to customize the menu in KDE and this applies not only to the existing menu. If you have installed new programs, which don't appear in the menu, or if you want to set alternative run options for an application, which is currently in the KDE menu and you need a second entry for the same application but with different parameters, you can add new menu items and submenus.
From the KDE menubar, select Edit → New Item or Edit → New Submenu to enter a new menu item or submenu, respectively. If you want to add a new separator in order to make your KDE menu neat, use Edit → New Separator.
In addition to adding new menu items and submenus and editing existing ones, you can also delete the ones you don't need. However, be very careful what you delete and pay attention not to delete a vital menu entry. Still, if you are sure that you want to delete a menu item or a submenu, select it in the left pane and click the Delete icon (the last icon in the buttonbar right under the menubar of the KDE Menu Editor dialog).