Does your monitor by any chance have a DVI port, or is it VGA only? It's much easier if it does have DVI as you could buy a simple HDMI to DVI cable to connect it with.
If it's only VGA, then you need an "active" adaptor to convert the digital signal into analog. You can easy buy these too, but they cost more and often have limited resolution.....but you probably aren't using 1080p anyway with a VGA monitor.