For commercial installation, perform the preliminary setup steps 1 and 2 above, then follow the steps in the README at https://github.com/xtuple/xdruple-drupal. These instructions walk you through the process of creating a new xTupleCommerce project. Basically, you assemble all the required parts on your local system, then create a new GitHub repository and push the project to the new repository. When those steps are complete, you follow the instructions in the project README to complete the installation.
