FREE Automatic Subscription Renewal?

[workplaybiz]

Hi,
I was wondering how you could have a lifetime membership to a section of the site without having to manually add the users to the usergroup again every couple years or so... Is there some way to automatically renew subscriptions for free after a set amount of time? I was also wondering if there was a modification to be able to give the users a cancel my subscription button or something like that so that they could cancel a monthly subscription without having to notify me. It would remove them from the usergroup at the end of the month and stop billing them after that last month. If a modification doesn't exist, can you point me in the right direction and tell me what would need to be done because I will try to create one.