- From menu, go to Tools -> Plugins.
- In the last tab (setting), you will see a update centers list (on left side) e.g. "Certified Plugins"
- You have to know your desire plugin is located in which update center.
- select that update center from list (e.g. Certified Plugins) and then from right side click on the "Edit" button.
- from the shown dialogue, copy text in URL text box (do not copy last part of URL, in this case "catalog.xml.gz", only copy the address of xxx.gz file e.g. "http://updates.netbeans.org/netbeans/updates/7.2/uc/final/certified")
- Now you can paste the URL in your browser and find your plugin in folders.
have a nice time.