As far as I know, the only way to do this is to open the Cheat Menu, click on the city that already has the Wonder, click Edit City, then Delete All Wonders, and then, go to the city you want to put it in, go to it's build menu, and "cheat build" the Wonder anew. I personally don't know of any other way, other than, I guess, hex editing, which I have no proficiency in.