If your plan is a manual renew plan then simply do not renew. Your subscription will atomatically lapse on the last day of the paid period. To renew later, simply log in and you will be taken to a screen to select a new plan, you dont need to create a new account.
If your plan is a rebill plan, we cannot cancel this for you. To cancel, simply log in to your Paypal account and in the recent transactions at the bottom of the home page you will see our transaction, and next to that is a "cancel" button. Simply click the cancel button. Your subscription will remain active until the last day that you have paid for. Please note you cannot re-subscribe to a rebill plan after cancelling it, this is a PayPal rule.