You may cancel your subscription at any time by going to your Account Settings (cog icon ⚙️ on the bottom left) -> Subscriptions.
Click on the View button of your active subscription and then click on the Cancel button.
That's it!
Let's say today is January 11th and your next renewal is on February 2nd.
If you cancel your subscription today, it will remain active until February 2nd and you will still have access to the program until that day since you have already paid for that period.
However, on February 2nd your subscription will be completely canceled, no further payment will be made, and you will no longer have access to the program.