To install a string hook is easy: Turn the tremolo over and just loosen the 2 screws that are attached to the brass colored load lever. It is attached to one end of the 2 springs underneath. Remove the 2 screws attached to the frame. The cam swivels freely. Remove the six fine tuners revealing three Phillips screws. Remove the three screws. The cam cage now lifts off easily from the cam (the part with the six string hooks). You need to drive out the pin that runs though the side of the cam cage. It locks all the sting hooks in place. Look on the side of the cam cage and look for the smaller, chipped side of the pin. It’s usually inset a bit into the cage body. The other side seems flush to the side wall. YOU PUSH IT OUT FROM THE INSET SIDE. Once it protrudes from the other side use a pair of pliers and grip it and pull it out easily with damaging the end of the pin. Pull it out only as far as the broken pin. Insert the new hook and gently twist the pin back through the string hooks eyes and gently re-tap it back in flush. It’s fairly simple. You will need a long thin object to push with. Try using a jewelers type .050” Allen driver available at radio shack.