the shared/webassist directory is not a part of your site. it is a folder on your computer.
the instruction for finding the users configuration folder are in the section of the linked article title:
For Windows users, they are as follows:
For Windows Users
-Open a Windows Explorer window.
-In the Address bar enter %appdata% and click Enter.
-Open the Adobe directory.
-Open the Dreamweaver folder for the version of Dreamweaver you are using.
-Dreamweaver CS4 and above users only - open the en_US directory.
-Open the Configuration directory.
once in the configuration folder, go to shared/webassist/eCart