How to break a lease without making myself look bad to future rentals?

If the roommate stays there then the lease is not broken. Getting removed from a lease is not breaking the lease. Getting removed from a lease does not create negative rental history. To get removed both the roommate & the landlord have to agree to it.

Talk to the landlord and tell her you feel she is dangerous and might go postal and you want to get away from her. But tell him the only way you can do that is if he evicts you both. Ask him what it would take for him to legally evict you. Then do it. You may take a hit but being safe is better than worrying about your rental history.

It depends on what the lease says. Read it. If there's a term in the lease that allows early termination that is your way out. If there is not an early termination statement in the lease talk to the landlord. If there is no term allowing it and talking to the landlord doesn't work out the way you would like the only way is to hang out until the end of the current lease and leave/vacate when it expires.

You cannot break the lease unless your roommate also moves out and the landlord allows it. He won't allow just one of you out of it. Check that your leases allows it and ask if your roommate will agree to move. Then go your separate ways. If your roommate won't move, then you are stuck through the end of the lease. You can move out but you will still owe the rent.

Talk to the LL first. No release from the lease without LL and roommate agreeing.

You can talk to the landlord and ask what he will take to break the lease. And get that in writing.

The simplest (although expensive) solution is to move without breaking the lease. You go live somewhere else immediately, but continue paying rent on the place where you have the lease, even though you are not living there.

Have you read the lease? Have you spoken with your landlord? These are the first two things you need to do. Every lease and landlord is different, and you won't know your options until you dig into the details.

Some landlords are willing to do roommate releases if both parties agree and the staying party can qualify for the unit by themselves. Some leases have buy out clauses that can be enacted. Some landlords/leases allow subletting or tenant replacement. Some don't. Hard to really help without any details.

At the end of the day though, you need to be aware that pretty much all of those options require the consent of EVERYONE who lives in the unit. Meaning, your crazy roommate will likely need to agree to let you out of the lease. I would be very, very careful with how you handle that. Unless or until you're legally out of the apartment, you're both financially responsible. Careful with how you proceed!

You need to ask the landlord if he will release you. He need not as you signed a contract. If you break the contract he is entitled to pursue you which may well affect future applications for accommodation.

Any abuse happening is domestic violence and the police need calling each and every time, you need to report it and get the crime report number and keep a diary of all and any abuse..... these can be used to get a restraining order against this roommate and that would include them not being allowed in the residence...so in affect they have to find somewhere else to live.

You both are equally and legally individually liable for 100% of the rent so if you/they move out the rent is still paid in full.

If you wish to leave then you still owe your portion of the rent, only via agreement with the other tenant and the landlord can you change the contract...eg if both agree that you can leave and they can get another roommate to sublet and pay the rent