You can convert an existing application to a Strolch agent, but this might be a bit daunting in the beginning. If you are planning on doing this, first create a test application using the maven archetypes, so that you can get a feel for the configuration.
Once that works, use the archetypes configuration to reconfigure your project to start as a Strolch agent.
Note: Beware to select the archetype pertaining to your use case: