To set up Jive for OCS/Lync, you need to install the Jive Extended APIs plugin.
Getting up and running with Jive for OCS/Lync is pretty simple. This topic should get you started.
The Extended API plugin JAR file can be downloaded from the Jive Software web site. This plugin supports multiple Jive products including this one. After you add this plugin, you'll need to restart Jive in order for the feature to become available.