How can I get rid of people who are already in the picture and add someone else to it?

Easy just use clone tool, most foto editing programs have it. anda just have to select part of the background near the part of the picture anda don't want ,in this case Eric, and clone over it. clone tool if very handy in things like this and since this a pretty simple background it should be pretty easy. in some cases the background is harder to clone but anda can also use a different background.

What I do is just make the other character you're putting into the crossver bigger, like with this picture, so that it's less obvious... But the clone thing is a good idea too. Here's what else anda can try. find an empty background and put both characters into the picture, like I did with my first femslash. Hope this helps a little

I’m not seriously sure.