Year long promotion is expiring.

I have a year-long internet plan with Xfinity that is about to expire. I am moving to a place that already has wifi. How do I make sure that my contract won't get automatically renewed? Do I have to go through a cancellation process to do this? If I go through the cancellation process, how do I avoid an early termination fee? I looked through my contract and there was no indication of automatic renewal after the year, but I am really worried that I will get charged.