You can zip and unzip a zipper by doing one of the following:
In the 3D window (or 2D window), drag the zipper puller.
In the 3D window (or 2D window), click the zipper.
Go to the Context view, in the Actions section.
Either drag the zipper image, or in Zipped, type in how zipped you want the zipper to be, from 0-100%.
For more information about the Actions section, refer to Zipper Actions Section.