Here’s the activation which takes place in the files for the cws-demo-importer plugin. In the file importer.php, find the cws_imp_get_option which starts around line 38 and add this to the start of the function:
if($name == ‘_theme_purchase_code’){return ‘abcd1234-ab12-cwst-13en-vatoelements’;}
You should now be able to install the demo content (I just did so on a test site).