Replying to O MY FUCKING GOD!

So yes, another good story to tell! My sister's boyfriend got kicked out of his house a couple of months ago and since it was hard for him to live and find a place to stay and shit my mother offered him to stay at our cottage in sutton for a while and landed him our entrance code but then he broke up with he so my mom asked him to move out which he told us he did. I was in Knowlton this weekend and I am going up to stowe tomorow so I decided I would sleep at the cottage tonight but when I got here all his stuff was still here and everything is dirty as fuck. There was like old garbage bags in the entrance , rotten fruits, old pop corn on the counter, empty bear bottles , old arizonas and shit. The heater was on, his clothes are in the washing machine, all of his clothes are all over the place downstairs !!! I called my mom and she was freaking out! He's not here rite now but he might get here tonight so I am freaking the fuck out and have no idea how to change the code in the entrance. anyway its a number lock anybody know how to change that shit?