How to restart rental movie download on 5S?

I Rented 4 movies last night. Two downloaded fine, but I ran out of space. I made room for them, but can't figure out how to get the downloads started again.

There is nothing but a play button in the movies in the rental section in the movie app, and they are no lower in my current downloads in the Store. The movies do appear in my movie rentals, as a grey box.