How to cancel a movie download on my iphone 4?

I accidentally rented an hd version of a movie that is 6gb. That is too big for my 8gb iphone 4. I want to download the standard definition version because that is smaller, however, I can't download it because the hd version is stuck in the "waiting for download" mode. How do I cancel the download?

You have to go to [iTunes]>[Downloads]>then do somethinglike hold it and it'll give you an option. I don't use apple and its been a while but that's what it looked like on iOS 5. I know I'm behind lol.