1.enable "My Widgets" in the sidebar by check following checkbox in "File--->Preferences"
2. after step 1, you can see that "My Widgets" appears in sidebar. click following menu: configure a Widget from...--->Features and Plugins on an Update Site
3. a dialog will pop up after step 2. enter a URL in the input box and click "Load" button, some features will appear in the list if exist. check the features you want to install and click next until finish.
NOTE: the URL will be like the format: "file:///e:\XXXX" if your plugin is in local (the XXX is name of the parent folder of site.xml), and will be like "http://dubgsa.ibm.com/~bodonova/public/smasher/latest/" if your plugin is on the web.