One thing to be aware of when undertaking work such as this is to ground yourself at the start and regularly through out the operation to avoid any build up of static damaging components. In an ideal world we would all have Anti-Static wrist straps and work mats, as this is not the case touch a radiator or PC case to dispel any static. Lever up the front edge on the bottom cover be careful not to over extend it due to the ribbon cable to the right side middle.