My new boss is disabled and I'm going to get them fired.
Is there a reason you want them to get fired?
He has no right to be my boss.
I don't think it's a very nice thing for you to get your disabled boss fired, especially if they did not do anything wrong. How about you invite them to dinner, and get to know that person, so that you don't feel such irritation against them?
It doesn't matter, I myself am probably going to get fired anyways.
It would be bad if you got fired, but wishing the same fate on your boss, especially because they have a disability is not very kind. Perhaps you can improve your own situation at work by changing your outlook and trying to be more positive. It might result in you being a better employee and you enjoying those you work with more.