I'm going to break into a neighbor's apartment, as I want to turn the stereo off that he has left on all weekend, on repeat no less.
Do you find his actions offensive?
Well, yeah. I've had it with that guy.
Although it's unacceptable that your neighbor left his stereo on, you should not break into your neighbors house. Doing so could lead to you getting into trouble. It is safer to report your neighbor for disturbance and let the proper authorities handle it.
It's fine. I'm going to send my neighbors an apology note and it will probably be okay.
While I get how your neighbor annoyed you and they shouldn't have kept their stereo on so loud, it's absolutely wrong and illegal to break into their apartment. An apology note won't cut it when you get caught and you will get into a lot of trouble. Perhaps just talk to them about the disturbance they caused you.