First step was ok, just place Hazelcast lib and configuration inside the libs folder of Tomcat. Next thing, if you don't want a separate WAR file, is to build a small Valve class that starts up / shuts down the Hazelcast node. The question is: What do you want to achieve with this, since for a practical use you will likely have to access the Hazelcast instance itself (which should be possible to place it as an attribute inside the HttpRequest).
Chris