Replace an image uploaded by the user

I want the users to upload the image but how do I give them the option to replace them if they change their mind and want something else that is to be uploaded.

As far as I see, there is no media manager API method to delete files in the backend? This would mean, I cannot create an app where my users can replace images they‘ve uploaded before? I mean, I could, but as said above, this will eat up my storage space. Or am I wrong? Is such a basic feature really missing?