Gridster Module:
The Gridster module is turned off by default in a typical website. You must request the module be turned on through a Help ticket request, but keep in mind that your site might not have the option to have Gridster enabled.
Request the Gridster module be turned on for your website.
Gridster Training Video
If you prefer to watch the Drupal 7 Gridster Training video on YouTube you can do so here