I have a 3100e which has a two-piece top half: the keyboard front and the rear cover with the display etc. No screw under the sticker on mine; assuming yours is the same it's probably the latch in the back holding you up:
3 screws under the front will release the keyboard (2 plastic latches inside the slot for the lid latch). Lift it up and out of the way and remove 2 screws holding the aluminum shield. Remove the shield, unlatch the keyboard connector and remove the keyboard.
Remove the three screws along the upper front and two screws from below at the rear. There is also a locking tab in the center of the rear joint between the upper and lower half; pry up carefully under the upper half with a knife or similar tool to release.
Check the battery while you're in there, it'll probably need replacement. Why do you want to open it up anyway?
mike