I hired a hitman to take out my grandma.
Why would you hire a hitman?
I hate the bitch so bad
You need to tell the hitman that you changed your mind and do not want him to kill your grandmother. You are just as guilty as the hitman himself and what you are doing is immoral and against the law.
Nah, I'm not going to change my mind about this.
You can't just go around having people killed because you don't like them. Do you want to be arrested? If he gets caught he will surely turn you in.