Hallo. I am using broadband provided by my landlord who lives on the floor above me. He has a router which allows me to connect to the internet ehrr threadless/no cord? (whatever its real name is im sure you get my drift

) pardon my english but technical translations come hard to me.
I am guessing that since the company providing the internet he is paying for have no clue who is connecting to the network (everyone within a certain radius can access it) i should be able to forcibly change my IP with them having no chanse to take permanent action against it? if they do shut it down i just change it again and again?
I tried that other tips but seeing i dont got direct access to the router its kinda hard i need to be able to do it directly from my computer.
Any ideas as to how i should proceed?