first count how many screw holes are in your mobo, then take out the equivalent number of male spacers. Align your mobo with the usb/parallel/game/vga/ holes on the side of your case...take note of the location of the mobo screw holes
then take out your mobo, get a screw driver...go to the corresponding location of "screw holes" with your mobo removed, screw in the male spacers in the corresponding holes
then align your mobo with the screwed in spacers, screw in regular screws in the spacers and voila!