Installing memory is very simple, 30 and 72
pin SIMMs had a notch on one side so the chip would only fit one
way, they are inserted on a 45 degree angle then fold up till they
click in place, but most likely you are installing the newer 168
pin or 184 pin DIMM memory. You will notice the DIMM will have two notches on
the bottom edge that will only match up with the memory slot one
way.
Once you have the Memory chip in the slot, press down firmly
till it snaps into place the little handles on either side should
pop up to grab the chip firmly, if you need to remove the chip
push these handles outwards and the chip will pop up.