I just took a vga cable from the vga socket to 1 of of my monitors and bought a dvi to vga adaptor and screwed it to the dvi connection, then hooked up a vga cable from that to my other monitor.
Dvi to vga adaptors dead cheap, I paid 50p for mine on the market.
This is what your after, £2.23 on Amazon but look around elsewhere.
http://www.amazon.co.uk/Cabling4Less...3277235&sr=1-1