How a user can stop being charged?

If a user wants to stop the recurruring payments via his details how can he do that? I mean without going to paypal? I'm just using paypal for the recurring payments. Any of my plans have just one pay option.

P.S: Besides that, How can I stop my payments here, I will pay again when the plugin is update it's being 2 months without a real fix.

Please let me know.