gday again, sorry for the misinformation, if you can drill through what is left of the gear then you will need a small stellite drill and a grease nipple and a good quality tap to suit( will need to be done on pedestal drill, dont use stellite in a hand drill) drill through whats left of the gear and tap thread for the grease nipple, it might be a little hard at first ( use starter tap first) but once you get through the case hardening it should become a little easier and use a metal cutting compund, install nipple and use a high pressure power grease gun ( caterpillar dealers will have one) and pump till it pops. found this trick for bullets that have lodged in gun barrels.