Preferably you add the webpart in your template.
Press the button "Edit Page" in the ribbon menu.
Press one of the two buttons.
Than choose the folder "Collaboration Manager" in the Categories Menu and then you choose the webpart.
You can change the position of the webpart with the dropdown-menu and add the webpart with the next button.
After that you have to edit the webpart. Take your cursor on the webpart and there will appear a little downarrow. Press the arrow and choose "Edit Web Part".
Select any of the columns. (Pest practice tip: Set the "Chrome Type" to "none". There will no heading be displayed and thus it looks cleaner later in the workspaces.)
Confirm your settings with the okay button and save the tempalte.
Don't wonder that there is no effect visible. The template doesn't have any data. Go to your workspace and synchronize it.