ball joint screw replaces the center panel screw for the wing(the 4? screws that are at the top of the wings.
the other ball joint is more tricky.
you need to pop the rubber grommet on the inside of your bonnet, close to where the hinge is on the bonnet, and then drill a small hole through the hinge and into the bonnet. drill the hole between the two bolts holding the hinge to the bonnet.(if that makes sence) but closer to the bolt that is furthest up on the hinge(i.e. closer to the sky..)
you then have the task of fitting the upper ball joint. you have to cram you fingers into the small hole where the rubber grommet was on the inside of your bonnet... whilst holding the small nut that the ball joint screws into ( i litrally glued the nut to the end of my index finger and screwed the ball joint in and the pulled my finger out) once that is done, pop the gas lifter onto the ball joints and do the other side in the same way. them when its all done, open and close the bonnet a fair few times to losen the mechanism a little and bed the lifters in and you should be good.
sorry for poor explanation, while since i did it, and no pics sorry, hope it helps. any more Q's just ask

rob