The pom.xml file is already configured to download dependencies, compile, and package this plugin. Just use the goals "clean package" and the DisguiseCraft jar file will be put in the /target folder.
Firstly, you'll need to get a hold of the dependencies ProtocolLib and Spigot. Then compile the whole pgDev.bukkit.DisguiseCraft package and subpackages with the dependencies in the classpath. I believe the command would look something like "javac -classpath .:ProtocollLib.jar:Spigot.jar pgDev/bukkit/DisguiseCraft/*.java". The classpath would use a : or ; depending on which operating system you are using. To package, place the compiled files into a .jar file alongside the plugin.yml file.