Contact your landlord or management company- don’t go around them. In other words, don’t try to sublet the apartment or find a new tenant without talking to the landlord first; they’re bound to find out from a super or doorman. This could create potential legal issues for you and your security deposit may be forfeited. Ask whether you are able to break the lease if you can find a new tenant to take over. If yes, ask if you would be assigning the lease to the new tenant.