Take the nock out. Put a drill bit inside of the arrow shaft, should not be tight and needs to slide freely. Put the nock back in.
With the insert end down, pointed to the ground, lift the arrow shaft upwards and then swing it back downwards. The drill bit should hit the insert and will drive it out after a few whacks. Do this in a safe direction so you don't launch the drill bit through a window, into someone's eye, etc.