There are 4 screws on the rear(2 either side of the hinges),remove these screws.With the bottom of the laptop facing up then remove the battery cover(should already be removed along with power supply and battery),there should be 1 shorter screw in the corner of the battery compartment,remove this.The full bottom panel should be slid towards the rear just under an inch.The panel should then just lift of revealing the memory slots.Hope this helps.
Devotee101
June 2011