Network bridge or repeater

Hi, I live in a 2 story house, with 1 wireless router “Zyxel prestige 660HW-61”, 1 desktop computer and 3 laptops which are all connected through wireless connections to that router. The problem that I am facing is that the router has to be on the second floor which causes no connectivity on the first floor. I was told to buy an Access point, and that we did. We bought “Trendnet wireless G Access Point TEW-430APB” that can be access point, access point client, bridge or a repeater. Now I am finding it hard to connect the router and the access point. Can somebody help me or guide me through this progress?