Press your finger on the widget and hold still for about 2 seconds. It will then allow you to drag the widget. At that point, a "Remove" option should appear at the top of the screen. Without lifting your finger, drag the widget until your finger is over the "Remove" option and then lift your finger. The widget will be removed from your screen at that point.
Alternately, if you don't want the app at all, uninstalling the app will also remove the widget. Uninstalling the app can be accomplished by using the same method as removing the widget, but touch and drag the app icon from the app drawer to the "Uninstall" option at the top of the screen.