Have this problem to this day on focus' , one way is to try and use a pair of side cutters to "grip" the roll pin not cut it then use the leverage that these give to pull the pin out by using the tip of the pliers to pivot around, I have seen people screw a self tapper into the roll pin and pull it out using this , but saying that I have also seen the gearbox having to be removed to be able to get the pin out !!!!!!!