If you have a Knopflerfish or Oscar setup, you don't have to change much. Just place the Concierge framework JAR in your working directory. Concierge is able to run with your existing init.xargs file or with your system.properties. You might have to adjust some startup properties. Additionally, Concierge does not feature the ServiceTracker service as part of the framework. So if your existing setup makes use of the service tracker, add the Concierge ServiceTracker bundle to your configuration.
By default, Concierge runs with no shell. To have a shell, just add the shell-X.jar to the initially started bundles. This shell is very small but features most things that you will need for managing and controlling your OSGi framework. For controlling Concierge graphically on small devices, there is a simple AWT-based GUI which should run on most platforms. Headless platforms can be controlled remotely by R-OSGi.