Forget bridge mode, forget static IP addresses and forget wifi repeaters. This is the quickest and easiest method to use a secondary modem/router to expand your Wifi coverage by configuring it as an access point.
For this tutorial I am using a TP-Link TD-W8961ND as my secondary router. It is a 300mbps Wireless N ADSL2+ Modem Router.
This method should be very similar on all modern routers.