Okay, I figured out that if you click on the broken link you can select to delete it, and this worked well. However, I didn’t see an option for renaming the file. If there isn’t already, there should really be an option for that. Having to rename the file on my hard drive and upload it again is silly.
I also wasn’t able to find out anything about this just from searching for things with keywords like delete wordpress file, and I spent a while trying. Unless it’s there already and I just somehow missed it, I think that this information (deleting uploaded files) should be listed in the part of the documentation that tells you how to upload files. I wanted to post a link to the page I saw in the WordPress help that mentions how to upload files without indicating how to delete them, but I can’t find it at the moment. I hope this information was helpful to someone.