add uml plugin to netbeans 6.9.1 in mac os

i have a java project maked with netbeans . I want to get UML diagram from this project .I founded this plugin http://blogs.oracle.com/JavaFundamentals/entr开发者_开发技巧y/generating_uml_from_the_netbeans but i can't find it in netbans upgrade tool . Can you help me please ? i use netbeans 6.9.1 and mac os x 10.6.7

The UML Plugin was supported only until NetBeans 6.7.1