Step 1 (uploading the widget):
In your Wordpress Dashboard, click Plugins on the left side of your screen and then click Add New (Plugins > Add New). After that, in the top of the screen in the main menu click Upload (next to button Search). This is the area were you need to upload trendMe widget .zip file. File which you need to Upload can be found here. (Download this file to your PC and remember where you have put it).
After that and in Upload area upload that downloaded file (widget .zip file) from your PC to Wordpress.