Technically, you can’t uninstall Office 2013 product keys, but the theory is that you can uninstall your copy of Office from one PC and reinstall on another. So, it was with much satisfaction that I managed to achieve said uninstall/reinstall that I had never before achieved, completely legal and above board, with a genuine proper paid-for key, but using “Office Toolkit” from a dodgy website. It’s sad I had to go to these lengths, but hey, why let MS get away with it? After all, I had genuinely paid for the key!
You need to use the “Enter Custom Key” option on the Product Keys tab. Now, some of you might be saying “Where do you get this Office Toolkit program from?” Well, if you have to ask you probably shouldn’t be doing it!