You should now be all set to run the importers with the following incantation:

$ ruby -r rubygems -e 'require "jekyll-import";{
      # options for this importer

Where MyImporter is the name of the specific importer.

Note: Always double-check migrated content

Importers may not distinguish between published or private posts, so you should always check that the content Jekyll generates for you appears as you intended.