When you sign up for a membership, you have a 14-day period where you can ask for a full refund. Following the initial 14-days, it will be a partial refund, which is calculated based on the time you have had your membership. As a Plus member, you have complete control over your membership at all times. You can manage your own membership through your Plus dashboard.
Simply click on my account > account > cancel my membership.
When you cancel your membership, you are returned to a free trial level membership, where you will continue to have access to all your course certificates. You can upgrade your membership again at any time.