The WordPress BMLT plugin has just undergone a radical rewrite. All three of the CMS plugins now share a common code base, so they present exactly the same administrative interface as each other.
NOTE: You may also find this plugin interesting.
First, download the plugin from the WordPress Plugin Repository. Once you have the plugin installed, go to the BMLT settings, and read this page for guidance on administering the plugin.
Once the module is set up, then read this page to get guidance on how to make the BMLT instances appear in your pages and posts.
You may also want to look at these pages for ideas and examples.