I have been struggling with a broken keyboard for a few months and am finally fed up. Randomly (not provoked by touch) my Q,W,R,Y,B, alt, and command keys will lock up, spamming my current screen with the letter (or in some VERY bad cases, closing all open windows). I have tried cleaning and replacing keys, and have decided I most likely just need a new keyboard. I have one now, but am stumped as to how to install it. I've gotten as far as removing the upper case, but can't figure out how to unlock the metal casing that is underneath the keyboard. Help?