How do I break my one year lease?

You don't give much by way of details.  If your landlord is in breach of the lease in some way, then you may have grounds.  For example, there is a safety code violation that has not been fixed after repeated requests by you for them to do so; or there is a neighboring tenant who is dealing drugs, etc.

Otherwise, there really isn't much that you can do unless your lease gives you an out.  For example, some leases allow for early termination if you are being transferred for your job or you lose your job.  Also, most states allow military personal to break their leases early if they are being re-assigned.  You need to review the terms of your lease.  See if there are any possible ways out.  You can then place a quick call into Legal Aid to find out the law in your state.  And obviously, you scan speak to your landlord and see if they may offer you a solution.

If, however,  you cannot get out of your lease, you will be responsible for all remaining rental payments.  That having been said, you should be aware that , landlords do have a duty to "mitigate" damages". That is to minimize their damages by re-letting the premises.  This means that if you break the lease, your landlord has to advertise to try to find a new tenant.  Once they do, you must be released from the remainder of the term. 

You can assist your landlord in finding a new tenant.  Possibly a friend or co-worker?  Also, if your lease allows or the landlord will permit, you can try to sublet your unit.  Therfore, you will stay have to pay the landlord rent, but someone else will be paying you.  You can more easily accomplish this by subletting to your sub-tenant for less than what you pay.  You then will make up this difference.  It's not the perfect solution but getting something from a sub-tenant is better than getting nothing.