Assuming they’re not epoxied, take the largest diameter, heavy drill bit that will still fit into the shaft and slide easily. Take the nock off, and drop the drill bit in. Then lift the shaft up so the drill bit is sitting at the rear of the shaft, and swing it down forcefully, so the bit hammers the rear of the insert. You might have to do it a few times. I’ve salvaged many arrows that would otherwise have been a lost cause this way.