I'm not familiar with your particular fan clutch, but I can say in general that you need to replace the clutch assembly. If the fan is still undamaged, which can be hard to tell if it is a metallic fan, but easy if a plastic composite (the plastic composite fans flex and generally return to their original configuaration unless a chunk if broken off) you can keep it and just get the clutch assembly. Having to use a chisel to gain clearance pretty much guarantees, in my opinion, that you need a new fan clutch.