I'm actively trying to get my professor fired
Why do you think that they need to be fired?
I don't know if it's true, but I think he's having sex with one of my girl friends.
Well first of all you should find out if this rumor is true. Sometimes false information gets passed around and it can be incredibly harmful. You should not try to get someone fired over a rumor.
I will. I just want the professor to go away so I'm trying to get them fired.
You should be absolutely sure that these rumors are true before getting someone fired, especially for something this harmful to someone's reputation. If it turns out not to be true, then you will have ruined this professor's personal and professional life based on lies.