I have already publish this extension in chrome's web store. So you can go to the download page and install it.
After installed the extension, you will see an icon in your toolbar.
Press the icon then you will probably see a popup showing this:
That's the expected result because you have not opened a WCL report page.
When you open a WCL report page, for example this one, and press the extension icon again, you will have this in the popup:
.
Pressing the analyze button in the popup and the extension will navigate to the WoWAnalyzer report page.