unplug all the devices which are connected with your thinkpad then switch off, remove battery. back side of the thinkpad there is a screw, unscrew it. thats it
The keys on the keyboard are designed to simply pop out without any damage. As long as you do not pry them sideways or twist them they should put out nicely if you use even a butter knife or a small, thin object for leverage. Just do on row at a time so they don't all get lost.
Switch of the laptop. Remove the accumulator. Remove the screw of the accumulator container. Remove the screw of the mini PCI hatch. Remove the screw under the mini PCI hatch. Turn the laptop and open the lcd display. Push the arm at the keyboards and take it out of the frame carefully.