You can install plugins into your CLC Workbench using the Plugins manager.
The Plugins manager is launched by clicking on the Plugins button in the top toolbar.

Please note that to install Plugins, you need to be running your Workbench as an administrative user.

Further details about handling plugins in the CLC Workbenches can be found in our user manual:
http://resources.qiagenbioinformatics.com/manuals/clcgenomicsworkbench/current/index.php?manual=Plugins.html