To download and install the plugin into your maven plugin repository, first make sure you are pointing to the AndroMDA team server in your maven.repo.remote property (i.e. maven.repo.remote=http://www.ibiblio.org/maven,http://andromda.sourceforge.net/maven). Then type:
maven plugin:download -DgroupId=andromda -DartifactId=andromda-translation-library-plugin -Dversion=3.3