how can I access Gujer matrix?

I can't find Gujer matrix, please how can I access it? I using WEST 2011

In the Model Editor:
- load a valid BlockLib.xml (or create a new one)
- select a Category in the Home | Category menu: this will enable the Gujer Matrix button
- click the Gujer Matrix button
See also: Ch. 8.3.2 of the User Guide.

Thanks.