To drop a Qstream you are currently enrolled in, log into your Qstream account and from your dashboard, click on the Qstream you want to drop from the Qstreams you are taking section.
Select the Qstream Options tab and on the bottom of the page, click on the Drop this Qstream button.
You will be asked to confirm that you really want to drop the Qstream. If you proceed, you are removed from the Qstream and all progress information on that Qstream is deleted. Once you've confirmed, this cannot be undone.