Simple Question

I almost feel dumb asking this but:

I'm using an iPad with the new Calibre 3.0.0 Content Server. I got that connected up and was testing different things and downloaded a couple of books and one cbr file.

I would like to delete the downloaded files and don't see how is done.

Can someone help me see what is probably pretty obvious? The CBR file is taking up a bunch of space I would like to reclaim.

Thanks in advance