I have a torrent that contains many files in it, but I don't want to download all of them because I need only few files among them. I am not downloading from a torrent client, but I am actually using put.io service that converts torrents into direct downloads for me.

I want to edit the .torrent file (or magnet link) in such a way that I get only those files which I need from the torrent. I tried by editing with text editors, but I am getting some crazy hash errors when I did that.

I have seen people editing trackers in a torrent file (using online editors and other editors), but none of them edited the list of files in the torrent file.

So, the question is:

How to edit a .torrent file (and save it back as another .torrent file) such that when you run that torrent file, it only downloads only those files you need?