Clone the source
$ git clone git://github.com/glenford/sbt-jetty-embed.git
Build the plugin and push to your local ivy2 repo.
$ cd sbt-jetty-embed/plugin
$ sbt update publish-local
If you rebuild the plugin (ie. build a new version) then you should in your own project(s) run:
sbt clean-plugins
sbt clean update package
This will make sure that you have the latest plugin, and ensure it extracts the latest startup file(s) into your project