After you have downloaded the .zip file and extracted the individual candy wrapper and invitation images to your hard drive:
Open Microsoft Word
Select Insert then Picture then From File then open the directory that contains your candy wrapper and invitation designs.
To add WordArt select Insert then Picture then WordArt.
After entering your preferred text, you can modify the colors by right clicking the text and selecting Format WordArt. You can change the layout or direction of the text by using the options available on the WordArt Toolbar.