I've replaced one's keyboard on an HP laptop last Saturday, thanks to this online instruction.
Basically, 5 screws in the battery side, two nearest to the back of the battery edges (back of laptop) and 1 in the memory compartment, need to be removed. Then the CAREFULLY pry away the top cover of the keyboard along its two frontal sides (left, right), carefully because there's fragile cable connected to the cover from beneath, same goes with the keyboard (remove by CAREFULLY sliding the keyboard towards the back of the laptop).