The free subscription trial is available for users who create a subscription profile using his or her PayPal account. (A subscription profile cannot be created by buying as a guest with a credit card). To get started with PayPal here.
Once the subscription profile is created, you will receive streaming access and 14-days to trial the service. Immediately after subscribing or anytime within 14-days, you can cancel the subscription profile without being billed.
To cancel your subscription profile, see "How to Cancel My Streaming Subscription".