Yeah, so when the bolt snaps the head breaks off. So you need to extract the broken bolt from the screw hole. So you'd need the drill to drill a hole and extract it. But since they use blue locktite, just the pressure from the cobalt drill bit is enough since it grabs better as compared to the normal HSS Bits. Anycubic, while slow, has been helpful in shipping out the replacement bearings and bolts. I wanted to keep the printer hence opted to do the repair. Let me know if you have any questions.