You should be able to access your router login page by powering it on, connecting your computer to it (using an ethernet cable for instance) and by entering
192.168.1.1
in your web browser (it could also be 192.168.0.1
). Make sure that you are not connected to anything else in the meanwhile (other WiFi for instance).
From there, you can configure it as you use to.
However, I'm not at all convinced that you can use it as a signal repeater : you would need a custom firmware for that. But from what I've read, the main alternative firmwares out there (openwrt, dd-wrt) don't support this router.