* Battery pack is just clipped in the back * Hard disk is removable with an extra maintenance hatch * DIMM can stay where it is * Keybord is fixed with five screws on the back * palm rest is fixed with another three screws, remove it in the same step as the palm rest * backup battery is not applicable for the x220 * pci cards can stay where they are * keyboard bezel clips out * lcd assembly can stay where it is * base cover assembly and speaker assembly can stay where they are
A better manual would be: * remove battery from the back * remove ssd from its slot * unscrew + remove keyboard and palm rest with keyboard bezel (this is pretty much one step trust me) * unplug all five cables * unscrew motherboard * take motherboard (to which the fan is attached) from case and do what you want with it
X220 maintenance is a 10 minute job for disassembly and reassembly combined.