having problems importing my website into iweb - help!!

I made a website for my business during a session on iweb at the macstore.

It is uploaded and live on the web domain.

I transferred all the files via a usb key and put into the sites folder in user.

I want to make some adjustments to that site, but cannot seem to access it via iweb on my imac.

When I go to users library and click on domain, it just opens iweb. When I cancel so that I do not want one of the templates, it switches iweb off.

How to I import the iweb folders into iweb?