What should I do if I want to stop a fight between my two good friends?

Pull back. If they're really friends, then they'll eventually get over it, if you're a real friend, you stay out of it. Less stress.

You may want to stay out of it, but if it bothers you that much you can make them meet eachother at your house face to face and have them talk it out thats what we did to two of oyr friends and it worked

I would try talking to them separately and try to figure out the exact problems each friend has with one another, then I would bring them together to try and resolve these issues, or to at least make some compromises.

Find the problem, list pros and cons that you could do to stop the fight, and if it doesn't work get adult help