tenant agrees to move out but how do Hold him accountable

[Rob Murden]

My tenant is three weeks late on rent, and he said he cant afford my place and has agreed to move out, however his word means nothing because he lies quite a bit, do I need to still file an eviction or have him sign a contract saying he agrees to move out in a certain time frame. Just looking for the easiest an fastest way to get him out. He's on a month to month lease and since i have taken over the house he has not signed a new lease with me.