I recently let one of my close friends from high-school back into my life, and after a few months of hanging out somewhat regularly I want her gone.
What do you not like about her?
I hate her for being so annoying
If she upsets you, then it might be better for the both of you not hang out with her. You can spend your time with anyone that makes you feel comfortable.
I'm going to  hang out with my other friends. I'm not going to make an effort to see her.
That is totally fine to do. There is no expectation that you must spend time with any one friend or group of friends.