I'm going to end a 2 year long friendship.
What is making you want to end a 2-year long friendship?
I always feel bored when hanging out with her.
It's completely up to you who you keep as friends, but keep in mind that ending a friendship hurts the other person as well. You should at least talk to them first to see if maybe you can improve the friendship rather than giving up on it.
I don't need to talk to them, I'm just going to break her heart.
Don't you think that can be kind of selfish? If they were truly your friend then you'll just be upfront and honest with them. It's the least you can do in this situation and your responsibility.