Put the widgetlist.xml file and the Widget folder at the root of your web directory and configure your web server so that your "localhost" or "local IP" address directly reaches your web directory.
After that, all you have to do is change the IP address in the widgetlist.xml file to the IP address of your server.
Create a MediaBrowser 3 folder at the root of the USB key. Then uncompressed the Emby_1.0.6_Europe_20160120.zip file that is located in the Widget folder in your folder MediaBrowser 3