Unlike Drupal I haven't yet managed to figure out how to put Zen cart in a separate directory under a website's webroot and still hide the directory name.
Zen cart takes a lot more time then Drupal to customize. I'll now describe the process of slightly modifying a default install of Zen cart so that it looks quite our own. So here goes the steps -
0. Download, uncompress and upload Zen cart in a directory under your webroot.
1. If you are on www.example.com and Zen cart is under the zen directory in your webroot, then goto www.example.com/zen/zc_install from your browser. This will fire up the installer software. What happens in the installer is not worth describing and I am moving to the next step.
2. To be continued.