回复：回复：这租约是什么鬼人给你准备的,没有押金吗?

OK, in this case I would suggest this:

1. Explain to them that a lease is a lease binding to both parties. If they just move out legally you can sue them for rent of the remainder of the term.

2. But since they have been good (?), you can give them an early termination paper to sign, that they pay(1) rent of full current month and any outstanding unpaid rent; (2) deposit withhold by you until the end of the month; if you did not find a new tenant by them the deposit is forfeited. Explain to them that it takes time and money to find a tenant (say a PM would charge a month's rent to replace a tenant).