Installation of Magnolia Packager is easy because it is implemented as Magnola module:

• Drop these jars into the {webapp}WEB-INF/lib folder of your Magnolia web application (for each instance)
  • packaging-2.1.5.8.jar
  • jaxen-1.1-beta-4.jar
  • magnolia-license-1.0.1.jar
  • bcprov-jdk14-124.jar
  • bcpg-jdk14-124.jar
• Start magnolia. A packages repository and a pack servlet will be defined, some files will be deployed.
• Append the content of {webapp}/admintemplates/pack/js/pack_tree.js to {webapp}/admindocroot/js/tree.js to enable the context menu functions
  
• Enter the license string in the config repository.
  Go to /modules/pack/license and enter the license string.
  
• Restart magnolia so that the modified configuration can take place

Login to Magnolia and you will see a "Packages" item in the AdminCentral menu.