Hello Marc,
you have this menu nearly everywhere 
It opens a page where you can choos to add this dashlet to existing or new dashboards.
On the dashboard view it willlead you to edit your dashboard, there you can edit the url’s for dashlets directly. Or you go to dashboard.ini for your user and edit in manualy. There is also a trick to add dashboards globaly for users or groups.
Regards,
Carsten