Now file the nubs only going in the direction the leads are sticking out. In the end you should shape it similar to the roundness of the gear.

The Blue Arrows point to the ends of the leads that need to be filed.

The Green Arrow Points to the center of the crack.

The Red Arrows indicates the direction you should go to prevent pushing the lead you placed in there out. Please note the direction is the opposite on the side not indicated in this picture.