So how do we get in without him noticing? Well, the easiest way is to cause a distraction. On the left side of his house you'll be able to find an electrical switch. You know where this is going. Flipping the switch will trip the electrics in the house, causing the neighbour to start looking at what's going on. This will cause him to open one of the doors in his house, allowing you to make entry, if you can do it undercover.