It may depend on your motherboard, but, at least on my abit, it goes in just like a SODIMM on a laptop. You slide the appropriate card edge into the contacts of the socket at a 30-45 degree angle to the motherboard. Then, you press the card flat into the socket, while pressing it into the contacts just enough to line the notches on the ends of the card with the tabs on the socket. When it is in all the way, the tabs will lock it into place.