How do I get out of my lease?

I hate where I live and I have 6 months to go on a one year lease. I live in a duplex and share a wall with the loudest most inconsiderate person on Earth. His tv was up so loud the other night it was literally vibrating my walls! My landlord never comes to fix anything when I put in a request. My neighbor is a druggie and had weird people over at his house all the time and they steal from him, so now hes installed motion detecting flood lights in the driveway we share! It is a nightmare, how can I get out of my lease as legally as possible? Any answers would be much appreciated.