Easy. You get to set the time, and then when it's that time you should already be inside your house (I suggest waiting inside a few minuites early). Then they just come inside and walk around for a while and leave. You don't really have to do anything at the time though. I think you have to stay inside. You can go into other rooms of your house though.
You have to be in the main room, not any other rooms. And you can't wait outside either. If you're not there at the appointed time, your neighbor will get mad at you.