The plugin installer is available at http://www.openprinting.org/download/printdriver/auxfiles/HP/plugins/hplip-$ver-plugin.run where $ver is your version of hplip.For example »www.openprinting.org/download/pr···ugin.run is the latest version.
http://www.openprinting.org/download/printdriver/auxfiles/HP/plugins/hplip-$ver-plugin.run