Comment by Fokeman:
Hi Robert, the best idea is to download Paint.net (a free program) which is relatively simple to use and for which we have already loaded instructions. This works best with Windows computers. If you have a Mac, then there are other programs which can do the job. If you are doing it all from your phone then it might be most simple to crop square and let someone else or a moderator trim your labels from square to round. Feel free to contact me via the message service to ask for advice.